CavMag Newsletter Winter 2009 January 2011 Issue 5 News from the Cavendish Laboratory Inside... £20 million donation to Editorial 2 revolutionise physics research Ferroelectric and Magnetoelectric Memories 2 David Harding (St Catharine’s, 1979, new technologies and new industries that will The Raymond and Beverly Natural Sciences), the Founder, Chairman be needed to meet the demands of a growing Sackler Fund for the and Head of Research of Winton Capital population on our already strained natural Physics of Medicine 3 Management, has pledged to donate £20 resources. The programme’s director is Richard million to the Cavendish Laboratory to Friend, the Cavendish Professor of Physics Nanomagnetism 4 set up and fund The Winton Programme and a world-renowned leading expert on the John Baldwin FRS for the Physics of Sustainability. His gift, physics, materials science and engineering (1931 – 2010) 5 the largest donation to the Laboratory of semiconductor devices. Remarking on Higgs Bosons Provide since its creation in 1874, will create a new the impact of the donation, Richard said: Bridges to Hidden Worlds 6 programme in the physics of sustainability, “Advances in fundamental physics have always applying physics to meet the growing had the capacity to solve very real problems. Athena SWAN Silver demand on our natural resources. This programme will support the people and IoP Juno Champion with the radical ideas Success 7 that bring practical From the Hubble to solutions - very much the James Webb Space the Cambridge way of Telescope 8 doing science.” The Lloyd’s Register Educational Trust supports The programme will students in Scientifi c provide studentships, Computing 9 research fellowships, and support for new New Workshop Course for academic staff as Graduate Students 10 well as investment in Developing the Cavendish research infrastructure Development Plan 10 of the highest level, pump-priming Cavendish News 11 David Harding for novel research Senior Physics Challenge, projects, support for Physics at Work & the “The Cambridge 800th Anniversary Campaign collaborations within the University and outside, Science Festival 2011 12 has an objective: ‘The Freedom to Discover’ and sponsorship for meetings and outreach and I am hoping I can give the scientists of the activities. Cavendish more freedom to discover,” says David Harding. “I studied theoretical physics at Since graduating from Cambridge in 1982, Cambridge, and the Cavendish has always had David Harding has become one of the most the reputation of attracting the fi nest minds successful fund managers in the world. Early in the world. While it is not quite as simple on he recognised the advantages of hiring as using physics to save the world, this is an individuals with science backgrounds. Winton opportunity to use, for example, quantum currently employs over 90 researchers with physics to develop materials with seemingly PhDs or Master’s Degrees in subjects including miraculous properties that could combat the extragalactic astrophysics, mathematics, growing effect humans are having on the statistics, particle physics, planetary science and planet. I want to encourage research to keep artifi cial intelligence. the skies blue.” “At its core Winton is much more than an The Vice-Chancellor, Professor Sir Leszek investment manager,” says David Harding. Borysiewicz, said: “The University is most “We are a scientifi c research centre using grateful to David for this donation, which is empirical methods to analyse data. The fi nancial truly exceptional both in its generosity and in its markets may be our laboratory but just like the vision of translating fundamental discoveries in Cavendish we are driven by research.” physics, to meet one of the most pressing needs of our generation.” The Winton Programme for the Physics of The donation will support programmes that Sustainability will launched and fully established www.phy.cam.ac.uk explore basic science that can generate the in 2011. Editorial Ferroelectric and Magnetoelectric Memories his edition’s news is dominated or about twenty is shown in Fig.2. The physics interest of by the magnifi cent donation years there such structures lies in how to optimize the Tby David Harding described Fhas been a dielectric layer of the ferroelectric material, on the front page. The Winton perceived need in in the example shown in Fig. 2 the layer Fund will support research in the microelectronics being made of lead zirconate-titanate. the general area of what we call industry, not just These devices have already had commercial the physics of sustainability. The for faster, cheaper success. For example, FRAMs are used in intention is to support a very wide memories of higher the Sony Playstation 2. range of fundamental and applied bit-density, but especially for non-volatile physics in the general area of memories. ‘Non-volatile’ means that the condensed matter physics, which stored information is not lost in the event is fostered by many groups in the of, for example, a power failure or if a Cavendish. All of these activities nuclear blast goes off in front of your will contribute to understanding intercontinental ballistic missile, or more commonly the cat trips over the power cord how physics can contribute to the on your PC. The way most computers work many sustainability challenges is with dynamic random access memories that society is facing worldwide. (DRAM). DRAMs are silicon chips that are We will also use the resource to very cheap, very fast, and very high density, facilitate collaborations with other but they are volatile. So it is not a good idea departments in Cambridge and our to store a million bank accounts in them, partner universities. A distinguished or even the fi rst draft of your dissertation. international management group In your PC, the information is processed in will be set up to oversee these DRAMs, but when you hit the SAVE key, activities. The formal opening of the it is stored on a hard disc that is slow but programme will take place in the fi rst non-volatile. If the DRAMs were replaced quarter of 2011. by a non-volatile equivalent, the hard disc could be eliminated resulting in smaller, At the same time, we are delighted to lighter, and far more robust computers with Fig. 2. The interior of each bit of the state- announce gifts from the Raymond and no moving parts. You could put such a the-art Samsung 64 Mb FRAM. Beverly Sackler Foundation to support computer in a tank, into a basketball, or into research in the Physics of Medicine and in-line roller skates... Basic physics problems have, however, the Lloyd’s Register Educational Trust for limited the commercial exploitation of this studentships in Computational Science. technology. Every two or three years the These are described later in this edition industry giants in microelectronics - IBM, of CavMag. Texas Instruments, Intel, and Motorola in the USA; Samsung and LG Electronics in The science theme of this edition is Korea; and a host of Japanese corporations ‘New Faces’. Recent appointees Jim such as Hitachi, Toshiba and Fujitsu - publish Scott, Russell Cowburn and James Wells an ‘Industry Roadmap’ which shows what describe their research activities, each the industry needs in the coming few of them bringing new approaches and, years. The road-map for 2005 required unquestionably in James’ case, extra the development of FRAMs with three- dimensions to the Laboratory’s research Fig. 1. A Samsung packaged ferroelectric dimensional, rather than two-dimensional portfolio. We wish them all success in random access memory. structures by 2010-2011. This is because their endeavours. the bit-density is limited by the capacitor One way to replace DRAMs is with non- area, or ‘footprint’, on the chip surface. In A notable achievement has been the volatile ferroelectric RAMs (FRAMs). conventional RAMs that involve resistors award of Athena SWAN Silver and IoP In a ferroelectric crystal, the ions can be and transistors, the areas involved are much Juno Champion Awards in recognition of displaced in two or more directions by smaller than those of the capacitors in our endeavours in Equal Opportunities, applying an electric fi eld of order 50 kV/cm. FRAMs. That is a strong fi eld, but across a thin fi lm particularly in the support of female One way to get round this problem is to members of staff. only 100-300 nm in width, it is a very small voltage, in fact, less than the 5V standard of fabricate three-dimensional nanotube all silicon chips. capacitors that stick out of the silicon Lastly, we have simplifi ed the way in chip and we have achieved this in a which gifts to Physics may be received In work I did in the 1980s at the Ramtron collaboration of various Cambridge online and this is described on page Corporation and Symetrix Corporation in University laboratories (Fig. 3). Using organic 10. We are most grateful to the the USA, we were the fi rst to make such ruthenium compounds we can fabricate Development Offi ce for making this ferroelectric memories. A good example good concentric electrodes inside and possible. We hope benefactors will fi nd of a packaged FRAM from Samsung is outside each tube, giving a large area, and this an effective way of helping with our shown in Fig. 1. This consists of eight 512 proportionately large capacitance, but a development efforts. kbit blocks each of which has 16 32-kbit small footprint. A related approach is to go sections. The interior of each bit of the down, not up, by fabricating deep trenches Malcolm Longair state-of-the-art Samsung 64 Mb FRAM with high aspect ratios (Fig. 4). 2 These materials are usually multiferroic, meaning magnetic and ferroelectric, and The Raymond and so there is the concept of writing the data electrically, which is very fast, voltage-driven Beverly Sackler not current-driven, and uses very low power, and reading the information magnetically Fund for the which involves no re-set operation, no fatigue and no endurance problems.