September 2019 - ITP-quantumseminare

today's meeting 13:45 in H42
by Joe Renes 24 Sep '19

24 Sep '19

Hi all, today we again have two student talks at 13:45. Victor Gitton will tell us about his semester project, entitled "Describing quantum clocks with hidden variables", and Simon Mathis will tell us about his master thesis at IBM with Ivano Tavernelli on "Simulating quantum field theory with a quantum computer". Best, -joe

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tomorrow's meeting 13:45 in H42
by Joe Renes 16 Sep '19

16 Sep '19

Hi all, Tomorrow we kick off the new format of the group meeting at 13:45 in H42. We have two student talks planned for the first part: Sebastian Stengele and Alessandro Tarantola will report on their respective semester projects. Afterwards, we will continue with our more informal, internal group meeting for PhDs and postdocs. We'll definitely end by 15:30; likely before. Best, -joe

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Fwd: ICS - Tue 17.09, 10:30 - Alexandru Gheorghiu
by Joe Renes 16 Sep '19

16 Sep '19

Hi all, Please see below for an additional talk this week by our visitor Alexandru Gheorghiu. Note that it will take place downtown tomorrow morning. Best, -joe ====================================================================== Tuesday September 17, 2019, 10:30, CAB H53 ====================================================================== Speaker: Alexandru Gheorghiu Title: Computationally-secure and composable remote quantum state preparation Duration: 45 minutes ====================================================================== Abstract -------- Quantum computers are expected to efficiently solve certain problems that are believed to be computationally intractable to classical computers. This raises the question: how can classical users efficiently verify the results produced by quantum computers? In this talk I will present a protocol between a classical polynomial-time verifier and a quantum polynomial-time prover that allows the verifier to securely delegate to the prover the preparation of certain quantum states. Throughout the protocol, the prover remains oblivious as to which state it was instructed to prepare. I will then show how this remote state preparation primitive can be used by the verifier to delegate general quantum computations to the prover and verify their results. The talk is based on joint work with Thomas Vidick: https://arxiv.org/abs/1904.06320

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Job offer
by mwoods 15 Sep '19

15 Sep '19

See below job offer. Best, Mischa -------- Original Message -------- From: Jesse Thaler <jthaler(a)mit.edu> Sent: 15 September 2019 14:27:56 BST To: Jesse Thaler <jthaler(a)mit.edu> Cc: Aram Harrow <aram(a)mit.edu> Subject: MIT CTP Junior Faculty Search Dear Colleague, We in the Center for Theoretical Physics at MIT are conducting a junior faculty (tenure track) search this year in all areas of our activities. We specifically encourage applicants working in quantum computing and quantum information, including high-energy, nuclear, condensed-matter, and atomic-molecular-and-optical physicists whose interests have a strong overlap with QI. We also welcome candidates who would strengthen connections between physics and computer science. Beyond QI, this search covers areas such as cosmology, dark matter, and astroparticle physics; particle theory in and beyond the standard model; quantum field theory and amplitudes; QCD including strongly coupled matter; and string theory, gravity, holography, and mathematical physics. I am writing to you to inform you about our search, and to ask for your assistance in identifying promising candidates. If you know of a promising junior theorist whom you think we should consider, we would appreciate it greatly if you could spend a few minutes to inform them of our search and encourage them to apply. Please also let me know directly of candidates whom you think are highly qualified. The deadline for applications is November 1, 2019, and we intend to carry out any interviews in February 2020. We are particularly interested in making sure that highly qualified women and underrepresented minority candidates are aware of our search and apply. If you are aware of candidates in these categories, we would appreciate it if you could make an extra effort to inform these candidates of the position and to let us know who they are. We would also appreciate you informing us of women and/or minority physicists whom you think might emerge as potential candidates in the near future. Further information about the position and application procedures is available at: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Facademicj… (There is a separate QI-focused ad at https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Facademicj… but it is part of the same search.) Thank you very much for your time and for any assistance you may be able to provide. Sincerely, Jesse Thaler ------ Jesse Thaler Associate Professor of Physics MIT Center for Theoretical Physics 77 Massachusetts Avenue, 6-318 Cambridge, MA 02139 Email: jthaler(a)mit.edu Web: https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jthale… Phone: (617) 253-3713 Fax: (617) 253-8674 MIT Physics Community Values: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fweb.mit.e… ------

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Fwd: Phd position in Vienna
by Lidia del Rio 11 Sep '19

11 Sep '19

FYI -------- Forwarded Message -------- A PhD-student position is available in the „Young Independent Researcher Group“ lead by Dr. Yelena Guryanova, Dr. Ämin Baumeler, and Dr. Costantino Budroni. This group is inter-institutional; it is affiliated with the Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Vienna, as well as with the Department of Physics, University of Vienna, Vienna, Austria. The research performed will be on the project „Emergence of Causal Order in Quantum Theory and Beyond“. The project deals with causality in the interplay between theoretical physics and theoretical computer science (see https://www.iqoqi-vienna.at/research/yirg-young-independent-researcher-grou… ) We are looking for a student with a background in Physics, Computer Science, or Mathematics, with interests in - Foundations of Quantum Mechanics - Quantum Information - Theoretical Computer Science We expect the position to start in November 2019. To apply please send your CV and a 1-page motivation letter to: Costantino Budroni: costantino.budroni(a)univie.ac.at Application deadline: 30th September 2019

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today's meeting 15:30 in E41.1
by Joe Renes 10 Sep '19

10 Sep '19

Hi all, Today Julien Gacon will tell us about his master's thesis at IBM. 15:30 in E41.1. Best, -joe

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Title and abstract for Thursday's talk
by Joe Renes 03 Sep '19

03 Sep '19

Hi all, See below for the title and abstract of Susanne's talk. Best, -joe Title: Thermodynamics and predictive inference Abstract: Technically, most machine learning algorithms solve some optimization problem, where the aims of the learning method are encoded into an objective function. While this optimization can be hard in practice, and might require serious work, the main conceptual problem is that of finding the objective. I investigate if and how physical considerations can be used to derive learning objectives, or, equivalently, rules for information acquisition and processing. All information processing systems are physical, and hence subject to fundamental physical limits. Here, we will focus on thermodynamic efficiency. There is a fundamental relationship between Shannon's mutual information and work, which can be easily appreciated in the context of information engines. This connection allows us to derive lossy compression from a ``least effort principle"---rate-distortion theory emerges. If we widen the scope to partial observability and the use of different temperature reservoirs, then allowing for maximal thermodynamic efficiency leads directly to the ``information bottleneck" (IB) method. This method has been widely used in machine learning and was extended to time-series modeling, quantum systems, and to the situation in which the observer actively changes the process it is learning about. Fluctuation theorems have helped clarify the thermodynamics of systems driven arbitrarily far from equilibrium, with, and without, feedback. The thermodynamics of classical, strongly coupled systems can be understood in a straightforward way by realizing that causal intervention offers a way to identify those parts of the entropy production that result from feedback between the subsystems. From this, the central relations describing the thermodynamics of strongly coupled classical systems follow in a few lines. I plan to spend some time on generalized, partially observable, information engines, and the derivation of the IB, and then either on discussing the thermodynamics of strongly coupled systems, or on explaining IB and generalizations in greater detail, depending on the interests of the audience. I would like to encourage a discussion to connect to quantum thermodynamics. Papers: Thermodynamics: S. Still (2019) Thermodynamic cost and benefit of memory. arXiv:1705.00612 G. E. Crooks and S. Still (2019) Marginal and Conditional Second Laws of Thermodynamics. EPL 125, 4, 40005 S. Still, D. A. Sivak, A. J. Bell and G. E. Crooks. (2012) The thermodynamics of prediction. PRL 109, 120604 S. Still (2014) Lossy is lazy. Proc. 7th Workshop on Information Theoretic Methods in Science and Engineering (WITMSE-2014), eds. J. Rissanen, P. Myllymäki, T. Roos, and N. P. Santhanam E. Stopnitzky, S. Still, T. E. Ouldridge and L. Altenberg (2019) Physical limitations of work extraction from temporal correlations. Phys. Rev. E 99 042115 Information Bottleneck and extensions: S. Still (2009) Information theoretic approach to interactive learning. EPL 85, 28005. S. Still (2014) Information Bottleneck Approach to Predictive Inference. Entropy 16(2):968-989 (2014) S. Still and W. Bialek (2004) How many clusters? An information theoretic perspective. Neural Computation, 16(12):2483-2506 A. L. Grimsmo and S. Still (2016) Quantum Predictive Filtering Phys. Rev. A 94, 012338 S. Still and D. Precup (2012) An information-theoretic approach to curiosity-driven reinforcement learning. Theory in Biosciences: Volume 131, Issue 3, pages 139-148. S. Still, J. P. Crutchfield and C. J. Ellison (2010) Optimally Predictive Causal Inference CHAOS 20, 037111 S. Still and J. P. Crutchfield (2007) Structure or Noise? http://lanl.arxiv.org/abs/0708.0654

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meeting moved to Thursday 11:30 E41.1
by Joe Renes 02 Sep '19

02 Sep '19

Hi all, no meeting tomorrow, but on Thursday our visitor Susanne Still will tell us about her thermo research. 11:30 in E41.1. I'll send around a title and abstract shortly. Best, -joe

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