March 2017 - ITP-quantumseminare

today's meeting 4pm in E41.1
by Joe Renes 27 Mar '17

27 Mar '17

Hi all, today Mario Berta is visiting from Caltech and will tell us about his latest research. Best, -joe

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meeting moved to Tuesday 4:30 E41.1
by Joe Renes 19 Mar '17

19 Mar '17

Hi all, due to an odd sequence of events, we'll meet on Tuesday this week. Alexandre Roulet, visiting from NUS in Singapore, will tell us about an implementation of a quantum refrigerator (see title and abstract below). Originally the Tuesday talk was planned in addition to the regular meeting on Monday, but overhauling the lecture notes and problem sets for the thermodynamics course has consumed more time than Philipp, our scheduled speaker, had planned. So we'll hear from him when things there are more settled. Best, -joe Title: Quantum Absorption Refrigerator with Trapped Ions In this work (arXiv:1702.08672), we report on the experimental realization of a quantum absorption refrigerator, one of the standard examples of a heat machine, using the modes of trapped ytterbium ions. The refrigerator is evolving under a trilinear Hamiltonian such that heat from the work mode is transferred to the hot mode, cooling down the cold mode in the process. By implementing the refrigerator in the pulsed (or single-shot) regime, we experimentally cool down the cold mode faster and to a lower occupation compared to the steady-state regime. We show theoretically that this feature is enabled by quantum coherence, as an incoherent evolution of the quantum refrigerator precludes the device from cooling further than the steady-state occupation. This is in agreement with previous predictions for qubit-based refrigerators and highlights the role of quantum coherence in improving the cooling efficiency of the quantum refrigerator. We also consider squeezed thermal states and find that they are not a useful resource for cooling further in the single-shot regime, comparing them with thermal states of the same average energy.

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no meeting today
by Joe Renes 13 Mar '17

13 Mar '17

Hi all, no meeting today since many of us are out of town. Best, -joe

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Zurich solstice of foundations: summer school and workshop, 18-23 June 2017
by Lidia del Rio 07 Mar '17

07 Mar '17

Dear all, Join us at ETH Zurich to celebrate 50 years of the Kochen-Specker theorem with a summer school on quantum foundations and a workshop on contextuality. Registration is now open at http://foundations.ethz.ch/ *Deadlines:* Application for student support: *15th April 2017* Registration for the school and/or workshop: *31st May 2017* *Summer school on quantum foundations: 18-21 June 2017 * *Lectures:* Roger Colbeck, University of York, UK – Bell inequalities Angela Karanjai, University of Sidney, Australia – Epistemic models Matthew Leifer, Chapman University, US – No-go theorems Lluis Masanes, UCL, UK – Axiomatic derivations of quantum theory Sandu Popescu, U. Bristol, UK – Quantum paradoxes Renato Renner, ETH Zurich, Switzerland – Interpretations of quantum theory Katja Ried, U. Innsbruck, Austria – Causality Ana Belén Sainz, Perimeter Institute, Canada – Contextuality Robert W. Spekkens, Perimeter Institute, Canada – Experiment for foundations Despite there being a large community actively working on quantum foundations, and several specialized workshops for experts, there has been a lack of events directed at junior researchers entering the field, particularly in Europe. This summer school on quantum foundations comes to fill that gap, providing a solid introduction to different approaches and problems within foundations. The school is mostly directed at PhD students and junior postdocs in quantum information and related fields who are interested on quantum foundations. Registration is also open to senior researchers and master students. *School organizers* Lídia del Rio, ETH Zurich (chair) Markus Müller, Western University *Contextuality workshop: 22-23 June 2017 **Speakers:* Simon Kochen, U. Princeton, USA Alastair Abbott, Institut Néel, France Joseba Alonso, ETH Zurich, Switzerland Jürg Fröhlich, ETH Zurich, Switzerland Nicolas Gisin, U. Geneva, Switzerland Otfried Gühne, U. Siegen, Germany Chris Fuchs*, University of Massachusetts Boston, USA Mark Howard, U. Sheffield, Canada Robert Raussendorf, U. British Columbia, Canada Ana Belén Sainz, Perimeter Institute, Canada Robert W. Spekkens, Perimeter Institute, Canada The aim of this workshop is to bring together to the ETH Zurich, the place where the Kochen-Specker theorem was conceived, leading researchers in all contextuality-related fields in order to develop broader perspectives, draw connections between different approaches, stimulate collaborations, and envision objectives for future research. *Workshop organizers* Adán Cabello, U. Sevilla Stefan Wolf, U. Svizzera Italiana Best wishes, Lídia

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group meeting schedule
by Joe Renes 05 Mar '17

05 Mar '17

Hi all, thanks everyone for participating in the doodle. It turns out that the best option overall is to keep the meeting as is, Monday afternoons. I regret we couldn't accommodate students in the QIP course, but there were no other options that worked for the rest of the group. Best, -joe

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