November 2016 - ITP-quantumseminare

talk tomorrow
by Lidia del Rio 01 Dec '16

01 Dec '16

Dear all, Tomorrow (Thursday) our visitor Giulio Chiribella will give a seminar - an introduction to quantum combs <http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.101.060401> - at 3pm, room TBA. Best, Lídia

1 1

today's meeting E41.1 @4pm
by Joe Renes 28 Nov '16

28 Nov '16

Hi all, today we'll hear from our guest John-Mark Allen, from the University of Oxford, on quantum causal structures. For a preview, check out https://arxiv.org/abs/1609.09487. Best, -joe

1 0

No meeting tomorrow
by Joe Renes 20 Nov '16

20 Nov '16

Hi all, no meeting as many of us are out of town this week. Don't forget to sign up for the itp Christmas dinner tomorrow if you want to attend (see the email from Denise). Joe

1 0

today's meeting E41.1 @4pm
by Joe Renes 14 Nov '16

14 Nov '16

Hi all, today we'll hear from Vilasini Venkatesh on her semester project with Rotem. Best, -joe

1 0

Talk by Christian Majenz, Thu 17 November, 15.00
by Christopher Portmann 12 Nov '16

12 Nov '16

Location: HIT E41.1 Date: Thu 17 November 2016 Time: 15.00 Title: Quantum non-malleability and authentication Abstract: Non-malleability and authentication are of paramount importance in classical cryptography, both in theory and in practice, e.g. internet communication. In this Talk I will introduce these notions in the classical and quantum information-theoretic setting, review some previous work, present recent results, and indicate applications to the setting with computational assumptions.

1 0

Fwd: Seminar - J. Home
by Joe Renes 11 Nov '16

11 Nov '16

Hi all, here is the info regarding Jonathan Home's talk, in case you have not already received it. It will take place in E41.1. Best, -joe ---------- Forwarded message ---------- From: Beatrix Huber-Hottiger <beatrix.huber(a)itp.phys.ethz.ch> Date: Thu, Nov 3, 2016 at 10:14 AM Subject: Seminar - J. Home To: itp-all(a)lists.phys.ethz.ch Dear All, Jonathan Home will be giving us an informal seminar next week on the recent progress in trapped ions that they have made in his lab. Since, quite a few of us at the ITP are interested in driven and dissipative systems, we thought it might be a good idea to get together and discuss. The talk will be on November 11 10.30 am in E 41.1 See you all there, Chitra

1 0

today's meeting E41.1 @4pm
by Joe Renes 07 Nov '16

07 Nov '16

Hi all, today we'll hear from Rotem. Again there is a theory colloquium at 16:45, so we'll keep the meeting short. Best, -joe

1 0

Seminar tomorrow 3pm, HIT E41.1: Yelena Guryanova on Multi-time states
by Lidia del Rio 01 Nov '16

01 Nov '16

Dear all, Yelena Guryanova from IQOQI, Vienna, is visiting us this week (until Thursday lunch time). Yelena works on thermodynamics, nonlocality and quantum foundations. She will give the following seminar talk tomorrow (Wednesday) at 3pm, in room HIT E41.1. Best, Lídia *_ _* *_Exploring process matrices via the formalism of multi-time states_**_ _* When describing or observing a physical phenomenon, it is generally assumed that there exists an underlying causal order to the events. The belief is that events which occur later in time can be influenced by events occurring at earlier times, but not the other way around. Recently, however there has been an intensified interest in the role that quantum mechanics has to play when describing causal order in physical phenomena. Principles fundamental and unique to quantum mechanics can be exploited in such a way that they appear to result in descriptions of processes with indefinite causal structures. In this talk we look at two formalisms. The first is that of multi-time states, first introduced by Aharanov and colleagues, who developed a time-symmetric formulation of quantum theory. Here, a quantum system at several different times is described by associating a quantum state to each time. The second work we look at is the process matrix formalism, introduced by Oreshkov, Costa, and Brukner. Here, the idea of the 'process matrix' was introduced as a possible generalisation of quantum states where the causal structure of events can be partially relaxed. Here, operations in local laboratories are described by quantum theory without assuming a global causal structure. At first glance, the two approaches appear to be completely different and unrelated. We show that every process matrix is shown to correspond to a two-time state (the converse link however does not hold in general). We also provide an extension of a result which characterises process matrices. The connection presented here allows us to apply new methods and concepts to the issue of physics with indefinite causal structure, open new questions and hopefully create a platform of discussion about the issues of time and causality in quantum theory.

1 0