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Home , Andrew Gold, Brian Josephson

Concepts and Discovery in Quantum Matter

IN CELEBRATION OF GIL LONZARICH’S SEVENTIETH

12–15 July Cambridge, UK Organising Committee Siân Dutton, Malte Grosche, Montu Saxena, Suchitra Sebastian, Mike Sutherland. Thanks to Helen Verrechia, the team of volunteers, and the Department of Physics. Introduction

Samuel Johnson once said

Curiosity is, in great and generous minds, the first passion and the last.

These words could have been written about Gil Lonzarich, one of the most distinguished of his generation. His science has not been driven by an attempt to capture nature in neat equations, but by an exploration of what is possible in systems which have never been looked at before, and which defy conventional explanations.

From his early work on , through his famous discoveries in , to his most recent work on unconventional metallic states, he has always been curious to see beyond what was known. In order to do so, he has developed experimental techniques which have allowed him to study and control the electronic properties of materials in extremely high magnetic fields and at very low temperatures. This work has opened up our knowledge of the quantum universe in complex systems, offering the prospect of completely novel technologies.

His list of honours and awards, from his election as a Fellow of the Royal Society, to the most recent award of the Kamerlingh Onnes Prize in 2015, show that he is regarded as a great mind. But, perhaps more importantly, he is also possessed of a generous mind. When not actually standing next to his latest experiment, he can be found in deep conversation with his colleagues and students, not propounding his view, but freely offering his knowledge and experience and listening carefully to others. It is no surprise that he is held in great affection by all who have worked with him.

The is one of the world’s most renowned Physics Departments. It does not retain this position by virtue of its historical discoveries, nor by its modern facilities: it does so because it can still attract the best minds, young and old, to come together in an environment where they can flourish. Gil’s contribution to the life of the laboratory has been crucial for almost 40 years. His passion for his work still burns bright, and, as we celebrate his 70th birthday, long may it continue!

Andy Parker is Head of the Department of Physics, . He has been a colleague of Gil for several years. 3 Editorial

he idea of a souvenir book for Gil’s 70th celebration has evolved. From Tthe first tentative idea of a few reminiscences as part of the abstract book, it has grown into an amazing collection of Gil anecdotes – alternately touching, inspiring, humorous – all California at Berkeley as a Regents’ Scholar heartfelt. Such is the warmth Gil inspires, from 1963 to 1967. In this period he a testament to the time and care he met Gerie who became his partner and pours into his multitude of students friend, developed a passion for sports and collaborators. In the process of (playing on the University soccer team), compiling the souvenir book, we have and between his studies worked part been overwhelmed by the memories time at a communication station on an of Gil that poured in, and struck by the uninhabited Pacific Island where he had sentiment expressed that it is a privilege the unforgettable experience of seeing to be able to say thank you. We would like nature untouched by man. to thank all those who contributed, your generosity is much appreciated. In 1967 Gil and Gerie married and moved to the University of Minnesota Suchitra Sebastian and Siân Dutton, in Minneapolis with the support of a Quantum Matter Group Corporate Fellowship. Gil’s research project with W. Zimmermann and L. A word from Gerie Nosanow involved an experimental study of superfluidity in3 He–4He mixtures. il was born in 1945 to Italian The long-term goal was to test the then parents on the Istrian peninsula, sensational prediction that superfluidity Ga small territory that has changed would survive in pure liquid 3He (a Fermi sovereignty numerous times and is now a rather than Bose liquid), albeit under part of Croatia. extreme conditions not yet readily available at that time. Shortly after the end of the second- world war his family moved to northern In 1969 with the support of a Killam Italy and Gil remembers growing up on Fellowship, Gil moved on from the field a beautiful farm bordered by streams of quantum liquids to that of interacting and an ancient castle (said to have been electron systems at the University of occupied by some of Attila’s hordes at the British Columbia in the beautiful city of end of the Classical Roman period). Vancouver. Gil’s PhD project with Andrew Gold aimed at understanding the factors Gil continued his education in America that determine the Curie temperature in where he attended the University of itinerant-electron ferromagnets such as 4 Soon after the completion of his PhD studies Gil took up a one-year post- doctoral position in Cambridge where he had the opportunity to work with David Shoenberg and . Though Gil and Gerie had only thought to have a grand adventure for a year in Europe, they ended up living in Cambridge longer than they had lived anywhere else. It turned out that Cambridge was meant to be the destiny location – the place where Gil had the opportunity, freedom, support and intellectual environment to explore and develop the problems that fascinated him.

This included the development of the technique for the study of quantum oscillatory phenomena in complex materials (beyond the elemental metals of main interest at that time), the use of inelastic neutron scattering to detect paramagnons (dissipative spin fluctuations), the study of the effects of THE “DIARY”. Here, on the right, is the special helium liquefier, designed by Kapitsa, which is of enormous paramagnons on thermal properties and value to the laboratory. Simply and effectively it on electron-electron pairing instabilities, produces supplies of the evanescent liquid gas - the investigation of quantum critical “like milk from a cow” say the researchers. Frank phenomena, and the search for new Sadler, laboratory assistant, makes it, sees enough is always on hand, watches carefully against waste. quantum states in high purity materials. The laboratory is expected to get by for ten years on its current stock of helium, which is a gift from the Canadian National Research Council. Frank Sadler with ’s helium liquefier and its original description in the Cavendish diary, 1937.

Fe, Co and Ni. This programme started with a new kind of experimental test of the applicability of Stoner’s theory and culminated some years later with the first formulation of a realistic expression for the Curie temperature for a ferromagnetic metal (in the limit where the exchange splitting is small compared to the Fermi Above and top left: Gil and Gerie soon after energy). they met in Berkeley, 1966. 5 Gil has been a member of both the the chance to work with one such Cavendish Laboratory and Trinity College hero, namely Frank Sadler, who was as a demonstrator, lecturer, reader very proud of having been Rutherford’s and professor of physics. He is deeply personal technician. He told me many honoured to have been elected a Fellow stories about the old Cavendish Lab. His of the Royal Society of and the favourite story was of the day when he Institute of Physics, and to have been walked into one of the labs to find JJ awarded the Europhysics (Hewlett- Thomson, and Piotr Packard) Prize for Experimental Physics Kapitza, each in their normal business 1989 (shared with H. Ott and F. Steglich), suit attire, kneeling on the floor with the Prize and Medal 1991, the their heads close to the ground. They Guthrie Medal 2007, the Rumford Medal were surrounding Kapitza’s novel 2010 and the Kamerlingh Onnes Prize helium liquefier that had recently been 2015. completed, struggling to catch a glimpse of the first drops of the precious liquid. His greatest privilege is to have had the This marked the beginning of research opportunity to work with amazingly in in the talented students and colleagues from all Cavendish laboratory and led to many over the world, who have taught him at advances over the years. One of these least as much as he has taught them. was the demonstration that the droplets Gerie Lonzarich was born in the State of that these great men were trying to see Utah in 1946, grew up in Southern California would at slightly lower temperatures and studied engineering and fine arts at condense into a superfluid state. the Universities of California at Berkeley and Minnesota at Minneapolis. She met and married Gil in Berkeley during the turbulent, but exciting, I have always been grateful to Gordon 1960s. Among her many activities she was a Squires for introducing me to the field founding member of Cambridge Energy Research of neutron scattering and making it and an administrator for the Quantum Matter possible for me to work at the Harwell Group at the Cavendish Laboratory. Nuclear Reactor to search for the elusive ‘paramagnons’. This required the A word from Gil modification of some of the existing apparatus and the technicians went ere I would like to recall some out of their way to help. One day I stories that involved researchers requested a long tube of ‘aluminum’. The Hin the Cavendish Laboratory in an procurement officer looked at me with earlier era, whom I met during my first surprise, but said ‘come back in three few years in Cambridge. days’. I soon understood his puzzlement – the material he eventually presented to In his public lectures as Cavendish me was not what I expected, but rather Professor, Brian Pippard rarely missed a hard-to-obtain long tube of ‘alumina’, the opportunity to praise the ‘unsung’ namely aluminium oxide, which in its heroes who formed part of the backbone crystalline form is sapphire. A more of the laboratory. When I first arrived important example of the capabilities in Cambridge I was fortunate to have of the technical staff I witnessed was 6 the development of a new type of superconducting wire that later helped Reminiscences to revolutionize the study of quantum about Gil oscillatory effects.

David Shoenberg was a very patient and ilbert arrived at inspiring teacher. He could also be very the University of entertaining. One day, during a long G British Columbia laborious calculation on the blackboard, as a graduate student dealing with a problem where it was all circa 1970 to work with too easy to drop a sign, he joked that Andrew Gold. I was on the sign ‘was the invention of the devil’. sabbatical in Nijmegen David had many successful interactions in 1976-77 and David Shoenberg came with theorists perhaps starting with to visit. At some point during his visit in the 1930s. Our interest to Nijmegen he asked to speak to me in singular quasiparticle mass and a privately because he had a story he breakdown of the Landau theory of a thought I would find interesting. He Fermi liquid on the border of magnetic knew that I had been a postdoc with order has its roots partly in David’s early Gilbert’s PhD supervisor Andrew Gold. discussions with Brian Pippard and Ted Gilbert had apparently recently arrived Holstein in the late 1960s and early 1970s in Cambridge with superb references pertaining to current-current interactions from Andrew Gold. My memory is a bit between conduction electrons. These vague, but Shoenberg was expecting ideas were among those that inspired a dynamic keen person to be in the lab our work on heavy fermion quasiparticles, first thing every morning churning out quantum critical phenomena, non-Fermi fabulous results. Shoenberg himself was liquids and unconventional forms of an early starter who believed in getting superconductivity. your work done during the day. But he said Gil would drift into the lab mid-day I have had the privilege of interacting or later and seem to have some vague with many talented and creative students plans for an experiment, but not much and colleagues - I am forever indebted seemed to be happening. This went on to them. Also I am grateful for the for some time. Shoenberg was beginning support from the Cavendish Laboratory, to question what sort of person they had Trinity College, the Royal Society and in Gil. Finally a day arrived that Gil had other scientific bodies. Over my career indicated was the day for an experiment. my greatest good fortune has been to But still he didn’t show up until mid-day have known and worked with Gerie, my and he didn’t seem to be doing much in lifelong partner and friend. Finally I am the afternoon. Shoenberg went home very grateful to the organizers for their at the end of day disappointed. The ideas and herculean efforts, and to all of next morning Shoenberg arrived to find the participants. beautiful results from Gil’s experiment on his desk. He then understood a bit more about Gil. 7 Jim Carolan was a research associate when Gil was a PhD student at the University of British Columbia. He is Emeritus Professor at the University of British Columbia. Thanks to Walter Hardy, also a colleague of Gil from the University of British Columbia, for providing us with this contribution.

il, I am very sorry not to be able to join you for your 70th birthday celebration – I am sure this will Thorsteinn Sigfusson with the Low G Temperature Physics group cryostat, circa be a very special meeting! From the 1980. moment you arrived in the Cavendish you have been a source of inspiration he photograph shows me to all of us. It was a delight to find you tending the cryostat in the Low in the Cavendish when I returned from Temperature Physics Group at the Paris in 1978 and I remember very clearly T Cavendish. I remember Gil and Brian our many unscheduled and extended Pippard discussing with me what I would conversations, ranging from the very plan for the future. I was in the process practical craft of winding pick-up coils of precooling the cryostat. I told them with 50 swg enamelled copper wire and that leaders of the Science Institute at the their optimum impedance matching University of Iceland were urging me to to lockin amplifiers, to the profound come home to contribute to science in new physics you were exploring with Iceland. Then Gil said with a smile: ‘The Ni Al. I was delighted that our common 3 good thing when doing low temperature interest in the use of high-pressure physics in Iceland, Thorsteinn, is that you techniques provided many opportunities do not need nitrogen for precooling - you for conversations about physics, new merely open the lab windows’! experiments, and of course, about almost everything else. You have made After an awards ceremony in Russia in the Cavendish a very special place for 2007, Sergei Kapitza, son of Pyotr Kapitsa, many generations of condensed matter the famous ex-Cambridge professor physicists – I am sorry not be able to say and a Russian national hero told me ‘thank you’ in person at your birthday that I was regarded as a son of Russian celebration. physics through the family tree: Kapitsa- Richard Friend is Cavendish Professor of Shoenberg-Pippard-Gold-Lonzarich- Physics at the University of Cambridge. He has Sigfusson. been a colleague and collaborator of Gil since Gil joined the Cavendish Laboratory in 1978. Thorsteinn Sigfusson did a PhD with Gil in the Low Temperature Physics group. He is Professor of Physics at the University of Iceland and Director General of the Iceland Innovation Centre.

8 first met Gil in the winter of 1979 when The early ‘80s was a great time to be as a 17 year-old I came up to Cambridge learning with Gil in the Low Temperature Ifor interview. I had prepared carefully. I Physics Group. The group had roots that arrived, said hello, sat down and listened. went right back to Kapitsa. Brian Pippard Gil was friendly, open, and talkative. I’m and Brian Josephson were also around to not sure I was asked a single question. provide guidance and inspiration, along After 90 minutes, Gil said, “Well, I guess with the pictures of Landau and Onsager that’s time”. A few weeks later the offer puffing thoughtfully on their cigarettes. arrived – evidently I was a good listener. There were no barriers then: theories Gil was quite different from anyone I’d didn’t need to be logical to be useful and met before. He’d had a colourful life – equipment didn’t need to be owned to born in the Istrian peninsula, he went first be brought in to the group. Anything to Italy and then onto Berkeley in the ‘60s. was possible. He heard give their final live concert.

Members of the Low Temperature Physics group, 1994-1995.

9 Workshop at Il Ciocco resort in Northern Italy, 2000. From left to right: Stephen Hayden, Christian Pfleiderer, Fabien Beckers, Karl Sandeman, Montu Saxena, Gil Lonzarich, Andrew Huxley, Markus Steiner, Piers Coleman, and May Chiao.

Gil was always very open. He used this hen I first learnt that this book openness to try out and pare down his was in the making I thought, philosophy. He loved brevity: the main W ‘What a wonderful idea! It’s all cryostat was marked with the short too rare to have the opportunity to thank instruction, ‘Think twice’. His attitude one’s teachers, now I have the chance’. towards complexity was, appropriately, I marvel at Gil’s extraordinary intuition more complex. Gil was fascinated by for the physical world, to identify which business and business thinking. He problems might prove fruitful and then had no interest in money but he was find the courage and confidence to fascinated by motivation and leadership devote one’s energies to it. I trusted his and predicted the growth of scientific judgement implicitly and was rewarded entrepreneurship in the Cambridge by a confidence that the work I was landscape. embarked upon would be successful. I’ve realised since what a tremendous support In 1989, after ten very rewarding years that was to me. with Gil, I left to help develop a fledgling technology company and, some There are few people who have years later, start my current business. played such a seminal role in my life When business meets technology it’s as Gil, and, amongst the teachers I particularly important to “think twice”, have encountered, none who has so measure everything precisely, and, above completely communicated the value all, listen. of intellectual curiosity and the sheer excitement of research. I remember Guy Newcombe was taught by Gil as an Gil first as a lecturer. I can see Gil now, undergraduate, and did a PhD with Gil followed by a Trinity College Junior Research Fellowship in standing at the front of that enormous the Low Temperature Physics group. He is CEO of hall. The formal part of the lecture is Archipelago Technology Group. over, people are drifting out; but he 10 has time, he always had time, to answer Sarah Law was taught by Gil as an questions. And when he did, for a moment, undergraduate, and did a PhD with Gil in the Low Temperature Physics group. She now works both a wonderful clarity would reign. Gil was as a landscape historian and storyteller, and is always available and generous with his completing a collaborative doctoral programme insight. But the experience of discussing involving Rufford Abbey and the Historical physics with Gil was more immediate Geography Group of Nottingham University. and intense than this. When we spoke I was buoyed by his wish for me to see what he could see and understand the il was an inspirational mentor, about pleasure that research can bring. I carry that physics and many other things awareness still, and can very occasionally too. How many people, blinded let myself into the secret garden, but only G for several weeks after double detached because I was first guided to the door. retina surgery, would invite his students I’m not sure that it isn’t more bearable to to his house and enthuse about how interesting it was to adapt to not being disappoint oneself than those we respect. I able to see? This enthusiasm characterised still remember the evening that Gil sent me Gil for me. It was, and is, mainly directed home to sleep while he worked through at physics, but he applies it to most other the night, calibrating the resistivity of my things as well. It is one of the key reasons tiny crystal so that I could fly with it to that so many of his alumnae have gone an experiment the next day. I felt both on to careers in physics. If you work with ashamed of myself and infinitely grateful. I Gil, you see a great in action, but received no criticism from Gil, perhaps he also a great thinker who so demonstrably knew that I could provide that for myself, enjoys physics. You also get to meet but thinking back over the event triggers Gerie, and realise how crucial she is in a much broader recollection: that of being Gil’s life. Looking back, I did not realise valued, the sense that your efforts, however the importance of some of these things slight, were making a contribution. during my time in Cambridge, but I do now. Things Gil did or said come back to I remember doubting my ability as a me regularly. They have a huge influence physicist, telling Gil one day that ‘I didn’t on the way I try to run my group, and the think I could be a physicist, because I didn’t advice I give my students. If any of that dream of physics’. I remember him listening next generation thinks as highly of me seriously, hearing me, and reassuring me in 25 years time as I do of Gil, I will regard both that intuition was the fruit of years myself as truly fortunate. of devoted application and that roads branch: I should feel free to change track; Andrew Mackenzie did a PhD followed by the important thing was to commit to a Royal Society University Research Fellowship the journey ahead. Because of Gil, I have in the Low Temperature Physics group and never regretted my time studying physics the Interdisciplinary Research Centre in in Cambridge. And after all these years, Superconductivity. He is Director of the Max- Planck Institute for Chemical Physics of in teacher is far too limited a word to describe Dresden. my relationship with him: dear friend comes closer. 11 was the Secretary of the Department n the early days, one of the major of Physics at the time). To continue our challenges to overcome was reliable discussion I came along and Gil suggested Idetection electronics. This is the story of that I should wait outside Mr Deakin’s office. how Gil ended up paying for a particularly He expected the meeting to take no longer expensive lock-in amplifier. To tell this story than perhaps ten minutes. After waiting for I need to mention that I spent most of my about 30 minutes, time was coming up for spare time in Cambridge playing volleyball me to leave for Harston to meet my friend for a team based in London. Since team to drive to London for volleyball practice. practice in London was twice a week I was really happy when a friend of mine, Following a rather short moment of intense who had a company car, joined the same contemplation, I decided to give up team and did most of the driving. For the waiting, got my things from the lab, jumped commute to London we met in Harston in my car and drove to Harston. However, (this is about 20 minutes drive south of it turned out that my friend didn’t show Cambridge), where I parked my car on the up; so after waiting for about half an hour side of the road until we returned late in the I eventually decided to drive back to the evening. lab. By the time I reached the Cavendish nearly two hours had passed since Gil had So here it goes. One afternoon I was once disappeared into Mr Deakins office. again discussing with Gil the urgent need for this piece of equipment, when Gil Following again a short moment of intense suddenly realised that he had to go to a contemplation I decided to take the odds meeting in Mr Deakin’s office (Mr. Deakin and go to Mr. Deakin’s office. Sure enough,

Quantum Matter Group Christmas dinner, 2008.

12 a few minutes after I took my place on a ran all the way down, what is now, the chair opposite the office the door opened J.J. Thompson Avenue in January of 1994 and Gil appeared. What can I say - he was Ias the dog which had appeared near the extremely sorry, and very, very apologetic fence of the small farm-house continued for letting me wait for such a long time. I to bark and growl. I stopped only when I just did not dare telling him the truth... Even finally realised that there was an unending worse, he immediately asked what he could fence between me and the dog. In my do for me. Admittedly, I was rather happy to panic I had zoomed passed a figure in blue ask him for the signature on the purchase corduroys and largish sports shoes, who order. This was about 23 years ago. Time to remained oblivious to the pandemonium apologise for not having been completely as he glided towards the incongruous grey honest and to thank Gil for all his patience buildings of the Cavendish Laboratory. I and all his support over the years. think he sort of looked sideways and gave a benign smile as I rushed passed him, the Christian Pfleiderer did a PhD with Gil in the Gil Lonzarich smile which all of us find so Low Temperature Physics group. He is Professor of therapeutic. I also had no idea that I was Physics at the Technical University of Munich. running to meet him and that despite the here was one memorable occasion fact he was just behind me, I had to wait which gave me a lasting impression another two hours before he reappeared of Gil’s lab presence. An abstract and no one could work out where he T had been in the interim. All part of the had been submitted to the APS March meeting, but with less than twenty- charming familiar tale to those already four hours to go, we still had no results. initiated! Wires shorted or broke, leaks opened on cooling, things did not look promising. But with Gil around progress occurred, quickly. We played on with the system until dawn, Gil enthusiastically, myself a little jaded. By about 4 am we had the first half-decent cooling runs, giving just enough time for the 6:30 am airport bus. For me, the lesson of the night was that focus, a tight deadline and a well-stocked lab can sweep away most obstacles - at least when Gil and his inexhaustible resourcefulness come into play.

Malte Grosche was taught by Gil as an undergraduate, and did a PhD with Gil followed by a Trinity College Junior Research Fellowship in the Low Temperature Physics group. He is University Reader in the Quantum Matter group.

Montu Saxena and Gil, 2013.

13 Andrey Chubukov and Gil in the combination room at Trinity College, 2013.

That was the beginning of a wonderful While on a flight with Gil last summer, mentorship beyond imagination. What nestled above the expansive Eurasian I discovered soon was that discussions steppe and listening to Gil ponder how with Gil that ranged from triplet-pairing the people dispersed across the vast land to the Roman Republic stemmed from mass below have formed cultures and his deeply thought out commitment to empires throughout the ages gave me understanding the ‘strongly correlated’ the feeling that whatever Gil does, he nature of science, society and the human gravitates towards the most fundamental condition. How to think beyond the and essential questions which ‘experts’ tend borders of anything is Gil’s legacy and to bury away. unending passion that is most contagious and motivating. Global Gil is what many refer to him in Central Asia and China, especially when he Gil has played a significant international agrees to come to dinners next week and role through a multitude of endeavours. all of sudden remembers that he will be in Just like in science, Gil takes risks in order Brazil instead! to draw in those at the ‘border’ of the known and comfortable. He has made Montu Saxena did a PhD with Gil followed by a Girton College Junior Research Fellowship in the an impact in Central Asia, India, Brazil, and Low Temperature Physics group. He is Principal China amongst other places where he has Research Associate in the Quantum Matter group travelled to promote a thriving research and Chairperson of the Cambridge Central Asia culture and national investment in science. Forum.

14 il’s undergraduate supervisions s for an anecdote, well, I were something of a legend and have several, but I will just G might be worth mentioning. As A communicate one of them. The you might imagine they were known second time I came to Cambridge it was for being very inspiring, but they were in 2005. I was dropping by to see Gil after perhaps even more famous for being of a meeting at Bristol that Gil was supposed rather unpredictable length. I remember to be at as well, but he was sick. As a one which went on for over two and result, I didn’t see Gil either in Bristol or in a half hours, despite being scheduled Cambridge. The morning I was to leave for one hour and with Gil having dealt Cambridge, I had just got out of the with the set issues within about 15 bathtub, and Gil called. He said, do you minutes. I think they demonstrate Gil’s have a minute? I said sure. Two hours exceptional love of this subject and later, the phone call was over, and I was his rather characteristic (and hugely practically blue (it was November, and I likeable) tendency to get carried away was staying in the New Room at Trinity). sometimes. They represent some of It was worth it, though. I have thoroughly my most inspiring memories from my enjoyed every conversation I ever had undergraduate years and a model for with Gil, going back to the first one that some of my later experiences with Gil I remember when I was in Grenoble in during my PhD. the 1980s. It was late (2 am I believe). Everyone was out celebrating Bastille Day. Dominic Forsythe was taught by Gil as an But Gil and I were sitting on a park bench undergraduate, and did a PhD followed by a Trinity College Junior Research Fellowship in the discussing physics. Quantum Matter group. He is a partner at the Patent Attorney firm J A Kemp. Mike Norman spent an early sabbatical in the Low Temperature Physics group, since when he has known Gil. He is Director of the Materials Science Division at Argonne National Laboratory. have very fond memories of discussions with Gil, ranging from physics to I politics, history and finance. He has t was actually my first visit abroad taught me analytical and critical thinking at the end of my PhD. I had a small in areas inside and outside the context I result about anti-ferromagnetic order of science, and to be a moral and in heavy fermions and was visiting Gil’s responsible citizen. It was a great pleasure group. My first interaction with Gil, I had and honour to have worked under the the feeling to meet ‘greatness’. You know guidance of a true thinker. ‘great scientists’ as you read in books. I was so impressed that when I started to Chris Ko was taught by Gil as an talk to him, I sat on his glasses and broke undergraduate, and did a PhD with Gil in the Quantum Matter group. She is a strategist at them. Just imagine my embarrassment... ! Morgan Stanley. Catherine Pepin has known Gil since her PhD. She is a Researcher in the Theoretical Physics department at CEA Saclay.

15 Cavendish Hall of Fame

The well found lab where Shoenberg was cocooned, To fight for research grants excused all need, Collapsed to leave Gil Lonzarich marooned! He had no plans to follow Pepper’s lead Raise funds for liquid helium to pay! In painful interviews with Howie he Proposed to liquefy a great new way More capital expense - less running fee! Through lack of nerve we failed this scheme to grow So Gil that truly lasting fame can’t hit The Cavendish museum would bestow For something better than Kapitsa’s kit! That goniometer Basinski brought To see how dislocations were arrayed From four necks copper’s orbit signals got This second chance for glory Gil’s mislaid! Can heavy fermions a show provide? A piece of gear or vivid image yield Explained for visitors through Longair’s guide Enshrine Gil’s wider status in the field?

Archie Howie has been a colleague of Gil in the Cavendish Laboratory, Cambridge since the time Gil joined. He is Emeritus Professor of Physics, and former Head of the Department of Physics, University of Cambridge.

Gil lecturing at the Institute of High Technologies, Kazakhstan, 2013.

16 Malte Grosche, Gil, and Patricia Alireza, 2015.

treasure so many memories of my years scientific breakthrough. Most of all, I think with Gil that it is hard to think of one about his smile when I tell him that he is Ior two that stand out. I have known way more optimistic than I am, especially him for 16 years and I feel privileged to when he explains a new idea and what have had in my life the opportunity to he’d like me to try, and I tell him I don’t get to know him, to work close to him, to think it is possible. The funny thing is, experience his brilliant mind, ideas and thanks to his optimism and motivational inspiration. I think of all the students I skills, I always end up trying those ideas have seen through the years walking out and often end up having to accept that of his office beaming after a chat with he was right. him, he never fails to motivate. I think of all our walks to Trinity in which he’d Patricia Alireza did a PhD and post-doctoral share his new great idea, his new vision fellowship in the Quantum Matter group, since when she has collaborated with Gil. She is a for the way we should move forward. I Research Associate in the Quantum Matter think of going with him to conferences group. in which everyone is asking for him but he’s nowhere to be found until his talk… the many wonderful dinners in which he would talk about everything from the Roman Empire to his views on politics, on the economy, or on the next possible

17 Members of the Quantum Matter group, 2014-2015.

Dear Gil, our paper in a hidden corner of Trinity that you had discovered, played tennis I so wish I could be present at the and ate Chinese food with Gerie and Cambridge celebration of your Big Suzy, and, in what was clearly unusual for 70 to share there with you and your you, dined together often at High Table, many admirers some memories of our where one evening I was thanked by one interactions and collaborations, but these of your colleagues for inspiring you to words will have to suffice. make a rare appearance there.

We have had so many happy and Our times together in the United States productive times together that it is have also been very special, beginning hard to know which of my Gil stories to with an early workshop in Los Alamos include, but let me start with Cambridge. that led us to collaborate on what is still one of my favorite papers, ‘The Quantum The ten weeks I spent with you in 2000, Criticality Conundrum’. A few years later, during an appointment you organized an evening at a symposium in Snowmass for me as a Visiting Fellow Commoner at was devoted to an early celebration of Trinity, are one of the highlights of my your Big 60; it was such a pleasure to scientific career. You could not have been hear so many of your former students a better host. We discussed physics at the speaking with enormous fondness of Cavendish almost every day, worked on their time with you. 18 During the decade that followed we have reasonable bedtime. Hanging up at two been together on many occasions and in in the morning after one of these four many different countries, including China hour conversations with Gil, I’m usually and Brazil, but the most recent time in filled with the endless sense of possibility. Aspen is perhaps the best. I hope it will This is what keeps me joyful about doing be the beginning of what will surely turn physics. I even sometimes feel excited into a most successful and productive I’ve managed to explain something eighth decade. to Gil. And then it gradually dawns on me that it has actually been the other With every good wish from Suzy and me way around… Gil has just, in his gentle to you and Gerie on this special occasion! way, let me think I’m the one doing the explaining, and has let me discover for David myself.

David Pines is a long-time collaborator of Gil has been far beyond a physics mentor, Gil. He is Founding Director of the Institute he has been a life mentor – for this I’m for Complex Adaptive Matter, Distinguished Professor of Physics, UC Davis, and Research truly grateful. Professor of Physics in the Centre for Advanced Study, University of Illinois at Urbana- Suchitra Sebastian has collaborated with Champaign. Gil since joining the Quantum Matter group as a Trinity College Junior Research Fellow. She is University Lecturer in the Quantum Matter Group.

I might not have become a physicist were it not for Gil. Gil is of course an inspirational physicist, but what resonates most with me is his gentleness of spirit. In the physics world, in the balance between being kind and right, sadly the former almost always loses. When I first met Gil, and for quite a while after that, this particular penchant of physicists made the physics world seem very harsh, and nearly drove me to leave. But Gil is almost the only person I know, who somehow, despite everything, manages to be both kind and right. For me, this has made all the difference in the often rocky world of physics.

Another quality that springs to mind when I think of Gil is his boundless enthusiasm. Our enthusiastic bubbling- over conversations that last through the middle of the night, often only end when Gerie reminds him that it is far beyond 19 Quantum Matter Group, 2015 20 Attendees, CDQM 2015

John Adkins, University of Cambridge Piers Coleman, Rutgers University Gabriel Aeppli, Paul Scherrer Institut Gareth Conduit, University of Bristol Patricia Alireza, University of Cambridge John Cooper, University of Cambridge James Annett, University of Bristol Nigel Cooper, University of Cambridge Meigan Aronson, Stony Brook University Thomas Croft, University of Bristol Dirk Backes, University of Cambridge Anne-Marie Cumberlidge, Queen Alexandra Hospital, Portsmouth Elisa Baggio-Saitovitch, Centro Brazileiro de Pezquisas Físicas, Brazil Seamus Davis, Jordan Baglo, University of Cambridge Angelo Di Bernardo, University of Cambridge Niladri Banerjee, University of Cambridge Isabel Dinola, University of Cambridge Mark Barber, University of St Andrews Francisco Dinola Neto, University of Cambridge Ganapathy Baskaran, The Institute of Mathematical Nicolas Doiron-Leyraud, Université de Sherbrooke Sciences Siân Dutton, University of Cambridge Ernst Bauer, Vienna University of Technology Takao Ebihara, Shizuoka University Dietrich Belitz, University of Oregon Stephen Edkins, University of St Andrews Christopher Bell, University of Bristol David Edwards, Imperial College, London Christoph Bergemann, Gloucester Research Moaz Elghazali, University of Cambridge Matthew Bird, University of Bristol Mikhail Eremets, Max-Planck-Institut für Chemie Andrew Boothroyd, University of Oxford Michal Falkowski, Institute of Molecular Physics Daniel Braithwaite, CEA Grenoble Vitaly Fedoseev, University of Cambridge David Broun, Simon Fraser University Zachary Fisk, University of California, Irvine Philip Brown, University of Cambridge Felix Flicker, University of Bristol Guoshuai Cao, University of Cambridge Jacques Flouquet, CEA-INAC, Grenoble Chris Carroll, University of St Andrews Dominic Forsythe, J A Kemp Consulting Claudio Castelnovo, University of Cambridge Sven Friedemann, University of Bristol Premala Chandra, Rutgers University Chris Frost, Rutherford Appleton Laboratory Hui Chang, University of Cambridge Peter Fulde, Institute for the Physics of Xiaoye Chen, University of Cambridge Complex Systems, Dresden Anson Cheung, University of Cambridge Hongmin Gao, University of Cambridge May Chiao, Nature Publishing Group Michael Gaultois, University of Cambridge Andrey Chubukov, University of Minnesota Valerie Gibson, University of Cambridge Ana Cid, Max Planck Institut für Festkörperforschung Paul Goddard, University of Warwick Christopher Clark, University of Bristol Kathrin Goetze, Dresden High Magnetic Field Laboratory Matthew Coak, University of Cambridge

21 Swee Goh, Chinese University of Hong Kong Gil Lonzarich, University of Cambridge Mihael Grbić, University of Tokyo John Loram, University of Cambridge Andrew Green, University College London Andrew Mackenzie, Max-Planck-Institute for Chemical Physics of Solids Laura Greene, University of Illinois at Urbana Champaign Yoshiteru Maeno, Kyoto University Audrey Grockowiak, NHMFL Tallahassee Matthew Maitra, University of Cambridge Malte Grosche, University of Cambridge Rhodri Mansell, University of Cambridge Kai Grube, Karlsruhe Institut of Technology Kazuyuki Matsumoto, Muroran Institute of Technology Sebastian Haines, University of Cambridge Alix McCollam, High Field Magnet Laboratory, Nijmegen Walter Hardy, University of British Columbia Keith McEwen, University College, London Marianne Haroche, University of Cambridge Andrew Millis, Columbia University Neil Harrison, Los Alamos National Laboratory Kazumasa Miyake, Osaka University Mate Hartstein, University of Cambridge Gunnar Moller, University of Cambridge Stephen Hayden, University of Bristol Daniel Molnar, University of Cambridge Chris Hooley, St. Andrews University Corentin Morice, University of Cambridge Archie Howie, University of Cambridge Paromita Mukherjee, University of Cambridge Yu-Te Hsu, University of Cambridge Bhaskaran Nair, University of Cambridge Nigel Hussey, High Field Magnet Laboratory, Nijmegen Vijay Narayan, University of Cambridge Andrew Huxley, University of Edinburgh Guy Newcombe, Archipelago Technology Group Adrian Ionescu, University of Cambridge Philipp Niklowitz, Royal Holloway, University of London Stephen Julian, University of Toronto Michael Norman, Argonne National Laboratory Hyeong-Jin Kim, University of Cambridge Ian Osborne, Science Steven Kivelson, Stanford University Hans Rudolf Ott, ETH Zurich Chris Ko, Morgan Stanley Sibel Ozcan, Camfridge Ivan Kokanovic, University of Cambridge Avradeep Pal, University of Cambridge Frank Kruger, University College London Christos Panagopoulos, Nanyang Technological Anna Kusmartseva, University of Loughborough University Calum Lithgow, University of St Andrews Andy Parker, University of Cambridge Peter Littlewood, Argonne National Laboratory Stuart Parkin, Max Planck Institute of Microstructure Physics Cheng Liu, University of Cambridge Catherine Pepin, CEA - Saclay Maude Lizaire, University of Cambridge Michael Pepper, University College London Malcolm Longair, University of Cambridge Toby Perring, Rutherford Appleton Laboratory Gerie Lonzarich, University of Cambridge Christian Pfleiderer, Technische Universität München

22 Benjamin Pingault, University of Cambridge Stefan Tautz, RWTH Aachen University Pavlo Portnichenko, TU Dresden Joe Thompson, Los Alamos National Laboratory Emma Pugh, University of Kent Steven Thomson, University of St Andrews Eugenia Pyurbeeva, University of Cambridge Stan Tozer, NHMFL Tallahassee Jorge Quintanilla, University of Kent Vikram Tripathi, Tata Institute of Fundamental Research Jean-Philippe Reid, University of St Andrews Alexei Tsvelik, Brookhaven National Laboratory Pascal Reiss, University of Cambridge Ian Van Beek, University of St Andrews Maurice Rice, ETH Zurich Alexander Vasiliev, M.V. Lomonosov Moscow State University Sam Ridgway, University of St Andrews Olga Volkova, M.V. Lomonosov Moscow State Daniel Rowlands, University of Cambridge University Stephen Rowley, University of Cambridge Hilbert von Lӧhneysen, Karlsruhe Institute of Technology Tanish Satoor, University of Cambridge Ross Walker, Vancouver, Canada John Saunders, Royal Holloway, University of London Nan-lin Wang, Peking University George Sawatsky, University of British Columbia Shinji Watanabe, Kyushu Institute of Technology Siddharth Saxena, University of Cambridge Thomas Whitehead, University of Cambridge Andrew Schofield, University of Birmingham Jedrzej Wieteska, University of Cambridge Suchitra Sebastian, University of Cambridge Heribert Wilhelm, Diamond Light Source Konstatin Semieniuk, University of Cambridge Neil Wilson, Camfridge Hajime Shinohara, University of Cambridge Sebastian Witt, Goethe Universität Thorsteinn Sigfusson, University of Iceland Yi-feng Yang, Institute of Physics, Beijing Michael Simmons, University of Cambridge Jan Zaanen, Instituut-Lorentz, Universiteit Leiden Robert Smith, University of Cambridge Karl Ziemelis, Nature Shoshana Squires, University of Cambridge Ke-Jin Zhou, Diamond Light Source Frank Steglich, Max Planck Institute for Chemical Gertrud Zwicknagl, Technische Universitat Physics of Solids, Dresden Braunschweig Markus Steiner, European Patent Office Hamid Suleymanov, University of Cambridge Veronica Sunko, Max Planck Institute for Chemical Physics of Solids, Dresden Mike Sutherland, University of Cambridge Karol Synoradzki, Polish Academy of Science Attila Szabo, University of Cambridge Louis Taillefer, University of Sherbrooke Hong En Tan, University of Cambridge

23 List of speakers and talk titles

Gabriel Aeppli Condensed Matter Physics in the Style of Modern Atomic Physics

Patricia Alireza The Role of High Pressure on Strongly Correlated Systems: a Review of our Techniques and Results – Past, Present and Future

Meigan Aronson Quantum Critical Dynamics in Layered YFe2Al10

Ernst Bauer Tuning Magnetic Instabilities of Non-Fermi liquid Ce3Pd4Si4 by Pressure and Substitution

Ganapathy Baskaran Theory of Quantum Oscillations and Majorana Fermi liquid State in the Kondo

Insulator SmB6 Dietrich Belitz Nature of the Quantum in Clean Metallic Ferromagnets

Andrew Boothroyd Unconventional Metallic Osmates

Premala Chandra New Insights from Experiment on Novel Ordering in URu2Si2 Andrey Chubukov Superconductivity near a Quantum Critical Point

Piers Coleman Kondo Insulators: Magnetism meets Topology

Seamus Davis Atomic-scale Antagonism between d-Symmetry Cooper Pairs and d-Symmetry Density Waves in Underdoped Cuprates

Mikhail Eremets Conventional Superconductivity at 203 K at High Pressures

Zachary Fisk Topological Kondo Insulators

Jacques Flouquet Quantum Phase Transitions in Ce 122 compounds: CeRh2Si2 and CeRu2Si2 Peter Fulde Superconductivity Caused by Intra-Atomic Excitations

Neil Harrison Resolving the Fermi Surface in Underdoped High Tc superconductors

Stephen Hayden Field Tunable Phases in Sr2Ru3O7 Andrew Huxley Ferromagnetic Superconductors

Stephen Julian Quantum Oscillation Study of Critical Behaviour in PrOs4Sb12 Steven Kivelson Macroscopic Character of Composite High Temperature Superconducting Wires

Peter Littlewood Gil Lonzarich and the remarkable robustness of the Fermi liquid (after-dinner speech)

Gil Lonzarich A Glimpse of the Future

Andrew Mackenzie The Intriguing Physics of Delafossite Metals

Yoshiteru Maneo Melting­­ the Correlated Electron under Non-Equilibrium Conditions - Mott

Transition in Ca2RuO4

24 Andrew Millis Superconductivity in the Hubbard Model and in Cuprates: what we know, what we think we know, and what we want to know

Kazumaza Miyake Quantum Critical Phenomena due to Valence Transitions in Heavy Fermion Metals

Michael Norman Correlated Defects in the Kagome Spin Liquid Herbertsmithite

Hans Rudolf Ott "Novel" Phases in Low-Dimensional Spin Systems

Christos Panagopolous Materials Design and Functionality in Low Dimensions

Stuart Parkin Electrolyte Gate induced Metallization and Structural Changes in Correlated Electron Oxide Thin Films and Surfaces

Catherine Pepin Quantum Criticality in Heavy Fermions and beyond

Christian Pfleiderer Topological Unwinding of Skyrmions in Chiral Magnets

Maurice Rice A Giant Anomaly associated with Superconducting Fluctuations in the Pseudogap Phase of Cuprates

George Sawatzky SmB6 a Coherent Mixed Valent Material in Momentum Space Andrew Schofield Quantum Multicriticality

Robert Smith Critical Dynamics of Spontaneous Symmetry Breaking in a Homogeneous

Frank Steglich Emergence of Heavy-Electron Superconductivity by the Ordering of Nuclear Spins

Louis Taillefer Nematicity and Fermi Surface Reconstruction in Cuprates

Joe Thompson Magnetism and Quantum Criticality in the limit of Low Carrier Density

Alexei Tsvelik Quantum Phase Transition and Protected Ideal Transport in a Kondo Chain

Hilbert von Löhneysen Entropy Landscape of a Heavy-Fermion System near Quantum Criticality from Anisotropic Thermal-Expansion Measurements

Jan Zaanen Strange Metals, Fermion Signs, and Entanglement

25 Programme

Sunday Monday Tuesday Wednesday 12 July 13 July 14 July 15 July 2015 2015 2015 2015 8:45 – 9:00 am Opening Remarks 9:00 – 10:15 am Novel Phases Novel Phases Electronic Structure 9:00 – 10:15 am 9:00 – 9:25 am Andrew Mackenzie Christian Pfleiderer George Sawatzky 9:00 – 9:25 am 9:25 – 9:50 am Yoshiteru Maeno Dietrich Belitz Stephen Julian 9:25 – 9:50 am 9:50 – 10:15 am Stephen Hayden Alexei Tsvelik Michael Norman 9:50 – 10:15 am Coffee Break Coffee Break Coffee Break 10:45 – 12:25 pm Unconventional SC Novel Phases Correlated Oxides 10:45 – 12:25 pm 10:45 – 11:10 am Frank Steglich Stuart Parkin Andrew Mills 10:45 – 11:10 am 11:10 – 11:35 am Kazumasa Miyake Gabriel Aeppli Hans Rudolf Ott 11:10 – 11:35 am 11:35 – noon Andrew Huxley Premala Chandra Andrew Boothroyd 11:35 – noon noon – 12:25 pm Arrival Laura Greene Peter Fulde Christos Panagopolous noon – 12:25 pm 12:30 – 1:30 pm Lunch Lunch Lunch 12:30 – 1:30 pm Materials Discovery 1:30 – 3:10 pm 1:30 – 2:30 pm Posters Posters Patricia Alireza 1.30 – 1.55 pm Zachary Fisk 1.55 – 2.20 pm 2:30 – 4:10 pm Heavy Fermions Unconventional SC Mikhail Eremets 2.20 – 2.45 pm 2:30 – 2:55 pm Ernst Bauer Andrey Chubukov Ganapathy Baskaran 2.45 – 3.10 pm 2:55 – 3:20 pm Meigan Aronson Catherine Pépin Coffee Break 3:20 – 3:45 pm Joe Thompson Maurice Rice 3:45 – 4:10 pm Piers Coleman Stephen Kivelson Looking ahead 3.30 – 5.30 pm Coffee Break Coffee Break Robert Smith 3.30 – 4.05 pm 4:30 – 5:45 pm Quantum Criticality Unconventional SC Andrew Schofield 4.05 – 4.30 pm 4:30 – 4:55 pm Hilbert v. Löhneysen Louis Taillefer Gil Lonzarich 4.30 – 5.15 pm Welcome 4:55 – 5:20 pm Reception Jacques Flouquet Neil Harrison Closing Remarks 5.15 – 5.30 pm Wine & 5:20 – 5:45 pm Jan Zaanen Seamus Davis Jazz

Darwin 6:45 pm – late College Conference dinner Trinity College 6:45 – 7.15 pm Pre-dinner drinks 7:15 pm – late Conference group Dinner in town photograph

Conference dinner.

After dinner speech: Peter Littlewood

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