Report on the ICTS Programme on Quantum Information Processing 5 December 2007 to 4 January 2008 Name of the programme: Quantum Information Processing Organisers: Jaikumar Radhakrishnan, School of Technology and Computer Science, TIFR, [email protected] Pranab Sen, School of Technology and Computer Science, TIFR, [email protected]. Duration: 5 December 2007 to 4 January 2008. Preamble: Quantum information processing is a thriving area of research that at- tempts to recast information processing in the quantum mechanical framework. Several remarkable recent works in this area have challenged our understand- ing of computation and shaken the foundations of well-established areas such as algorithms, complexity theory, and cryptography. Over the last decade, fol- lowing Peter Shor’s efficient quantum factoring algorithm (1994) and Grover’s quantum search algorithm (1996), several works have consolidated and gener- alised the insights obtained in these early works. In parallel, fundamental issues have been addressed in the area of quantum information theory, entanglement, quantum communication complexity, quantum cryptography etc. In 2002, TIFR organised a very successful successful event on a similar subject under the title Quantum Physics and Information Processing. Several developments have taken place in the area Quantum Information Pro- cessing in recent years. The purpose of the present program was to get the re- searchers in India, and TIFR in particular, acquainted with these developments. Structure of the program: The program was split between two locations: TIFR, Mum- bai, and India International Centre, New Delhi. We invited (to TIFR) experts who had made significant recent contributions, especially in areas where there is strong interest in TIFR, e.g. Quantum Information Theory, Quantum Algo- rithms, Quantum Communication Complexity, Quantum Interactive Proof Sys- tem, Quantum Lower Bounds. In addition, we organised a workshop in New Delhi. This workshop called QIP 2008, was the eleventh in the series of QIP workshops. This event will feature ten invited talks showcasing the most significant work in the area in the last year. The detailed program of the workshop is attached. Pedagogical lecture courses: To set the stage and acquaint students with the area, two tutorials were included in the beginning of the QIP 2008 Workshop in New Delhi. • Ronald de Wolf, CWI Amsterdam, Quantum computation and Shor’s fac- toring algorithm (tutorial). • Scott Aaronson, An invitation to quantum complexity theory (tutorial). Seminar speakers (at TIFR): The following experts visited TIFR in this period, in- teracted with members of the STCS faculty and gave talks. 1. Ronald de Wolf, CWI Amsterdam (5 Dec to 11 Dec 2007). Seminar: Fault-tolerant data structures (10 Dec 2007) 2. Avi Ben-Aroya, Tel-Aviv University (23 Dec to 25 Dec 2007) Seminar: Quantum expanders (24 Dec 2007) 3. Frederic Magniez, LRI Orsay (22 Dec to 28 Dec 2007) 4. Rahul Jain, University of Waterloo (23 Dec 2007 to 4 Jan 2008) Seminar: Direct-product theorems in quantum communication complexity 5. Hartmut Klauck, University of Frankfurt (23 Dec 2007 to 4 Jan 2008) Highlighted works The steering committee of the workshop selected ten works speak- ers whose works most influenced the field in the last year. The list of invited talks appears as part of the attached program. We have noted here some of the most striking presentations. 1. Andris Ambainis, University of Latvia and University of Waterloo. Prof Ambainis is the originator of several striking ideas in quantum algorithms and lower bounds. In his prolific career, he has made several signifi- cant breakthroughs in these areas. He is a co-author of the paper Every NAND formula of size N can be evaluated in time N 1/2+o(1) on a quantum computer Authors: Andris Ambainis (Waterloo), Andrew M. Childs (Cal- tech), Ben W. Reichardt (Caltech), Robert Spalek (UC Berkeley), Shengyu Zhang (Caltech), arXiv:quant-ph/0703015 This is perhaps the most signif- icant work on quantum algorithms in view of the novel techniques used, and it solves a problem that remained open for several years despite a lot of attention. Ambainis spoke about this work at the workshop. In fact, this work was considered so important that the Steering Committee decided to devote two talks to the subject, the other one by Ben Reichardt. 2. Ben Reichardt, Caltech. He is a co-author of the paper on quantum algo- rithms for NAND-formulas. He presented recent extensions of the above mentioned work using a different perspective. 3. Dorit Aharonov, Hebrew University. She is the author of some highly ac- claimed recent results, including the very recent result Polynomial Quan- tum Algorithms for Additive approximations of the Potts model and other Points of the Tutte Plane with Itai Arad, Elad Eban, Zeph Landau. quant- ph/0702008 (February 2007). In this work, she used novel methods based on knot theory in order to give quantum algorithms for highly important problems in discrete mathematics and physics. 4. Patrick Hayden. He recently disproved an important conjecture about quantum channels: The maximal p-norm multiplicativity conjecture is false, arXiv:0707.3291. This is considered to be a breakthrough in quantum in- formation theory. 5. Oded Regev, Tel-Aviv University. He is a leading expert on computational problems on lattices, and quantum and classical interactive proofs. He has 2 several algorithms and lower bounds in both quantum and classical models of computation. He spoke on his fundamental work on “A hypercontractive inequality for matrix-valued functions. 6. Falk Unger, CWI Amsterdam. He is one of the authors of the recent lower bound on fault-tolerance threshold of quantum computation. He is an up- coming young researcher who has also worked on non-locality in quantum information. He spoke at QIP 2008 on his work on fault-tolerance. 7. Renator Renner, Geneva, spoke on Generalized Entropies, and its applica- tions to extracting quantum randomness. Non-speaking participants Please see below for the complete list. Conclusion of the program The ICTS program on Quantum Information Processing was successful in bringing together an outstanding set of researchers and ex- posing the audience to the latest work. The visits to TIFR by these researchers helped in obtaining a deeper understanding of these results and the techniques used in obtaining them. Everybody who attended the events thought highly of the program. We have put together the complete archives of the talks, and hope to make them available through the ICTS: at http://icts.tifr.res.in/sites/QIP-2008 (this site is under preparation but the talks are accessible). We believe the timing of the event did not allow some other scientists to spend longer periods in India, and in future such programs should preferably be organ- ised differently, with greater focus on people spending more time in Mumbai. Regrettably, the participation from Indian researchers in the area was rather low. We had hoped for large student participation (as was the case in QPIP 2003), but that did not happen. More effort must be made in terms of publicity to attract this section to such meets where cutting edge work is being discussed. We are grateful to ICTS for supporting this event. List of contributed papers accepted for 30 minute talks at QIP 2008 1. Oded Regev and Ben Toner. Simulating Quantum Correlations with Finite Com- munication. 2. Graeme Smith. The private classical capacity with a symmetric side channel 3. Julia Kempe, Hirotada Kobayashi, Keiji Matsumoto and Thomas Vidick. Using Entanglement in Quantum Multi-Prover Interactive Proofs 4. Gabor Ivanyos, Luc Sanselme and Miklos Santha. An efficient quantum algo- rithm for the hidden subgroup problem in nil-2 groups 5. Andrew Cross, Graeme Smith, John Smolin and Bei Zeng. Codeword Stabilized Quantum Codes 6. Toby Cubitt, Aram Harrow, Debbie Leung, Ashley Montanaro and Andreas Winter. Counterexamples to additivity of minimum output p-Renyi entropy for p close to 0 3 7. Nikhil Bansal, Sergey Bravyi and Barbara Terhal. Classical approximation schemes for the ground-state energy of quantum and classical Ising spin glasses on planar graphs 8. Simon-Pierre Desrosiers and Frederic Dupuis. Quantum entropic security and approximate quantum encryption 9. Julia Kempe, Oded Regev and Ben Toner. The Unique Games Conjecture with Entangled Provers is False 10. Gilles Brassard, Anne Broadbent, Joseph Fitzsimons, Sebastien Gambs and Alain Tapp Anonymous quantum communication List of contributed papers accepted for 20 minute talks at QIP 2008 1. Ivan Damgaard, Serge Fehr, Louis Salvail and Christian Schaffner. Secure Iden- tification and QKD in the Bounded-Quantum-Storage Model 2. Jean Christian Boileau, Lana Sheridan, Martin Laforest and Stephen Bartlett. Quantum Reference Frames and the Classification of Rotationally-Invariant Maps 3. Ivan Damgaard, Serge Fehr, Renato Renner, Louis Salvail and Christian Schaffner. A Tight High-Order Entropic Quantum Uncertainty Relation With Applications 4. Stefano Pironio, Antonio Acin, Nicolas Brunner, Nicolas Gisin, Serge Massar and Valerio Scarani. Device-independent security of Quantum Key Distribution 5. Stephanie Wehner and Andreas Winter. Higher entropic uncertainty relations for anti-commuting observables 6. Stefano Pironio, Miguel Navascues and Antonio Acin. Quantum probabilities, semidefinite programming, and optimization over Hilbert spaces 7. Zhengfeng Ji, Jianxin Chen, Zhaohui Wei and Mingsheng Ying. The LU-LC conjecture is false 8. Scott Aaronson. Quantum Copy-Protection 9. Julia Kempe, Hirotada Kobayashi, Keiji Matsumoto, Ben Toner and Thomas Vidick. On the Power of Entangled Provers: Immunizing games against entan- glement 10. Daniel E. Browne, Elham Kashefi, Mehdi Mhalla and Simon Perdrix. Deter- minism in Measurement based quantum computation 11. Dan Browne, Matthew Elliot, Steven Flammia, Seth Merkel, Akimasa Miyake and Anthony Short. Phase transition of computational power in the resource states for one-way quantum computation 12. Aram Harrow. Quantum expanders from any classical Cayley graph expander 4 13. Tsuyoshi Ito, Hirotada Kobayashi, Daniel Preda, Xiaoming Sun and Andrew C.- C.