April 2026 - ITP-quantumseminare

Next Monday's QIT seminar
by Ladina Hausmann 29 Apr '26

29 Apr '26

Hi all, Next week, Leonardo Valente will talk about “Towards Information Measures for Quantum Reference Frames”. See below for the abstract. The talk will take place on Monday at 15:00 in HIT K 52. Best, Ladina %%%%%%%%%% Title: Towards Information Measures for Quantum Reference Frames Abstract: We explore methods for extending von Neumann information measures to systems without a single tensor-product structure, focusing specifically on Quantum Reference Frame (QRF) settings. In particular, we seek a meaningful notion of mutual information defined across different QRFs. To address this challenge, we propose two distinct approaches. First, we introduce QI-Measures, a framework that establishes a set-theoretic structure for von Neumann information quantities, revealing unexpected implications for strong subadditivity and operational interpretations, while extending entropic measures to new contexts. Second, we utilise an algebraic approach to identify subsystems within QRFs, thereby defining an extension of mutual information applicable to the non-factor algebras inherent in these relational settings. Together, these frameworks provide a robust basis for quantifying information in the absence of a fixed subsystem structure, uncovering previously unexplored informational properties of quantum systems.

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Merci pour la reponse itp-quantumseminare@lists.phys.ethz.ch,
by Mr Alain 29 Apr '26

29 Apr '26

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Next week's QIT seminar
by Ladina Hausmann 24 Apr '26

24 Apr '26

Hi all, Next week, İnci Anali will talk about “A Quantum Circuit Model for Black Hole Evaporation”; see below for the abstract. The talk will take place on Monday at 15:00 in HIT K52. Best, Ladina %%%%%%%%% Title: A Quantum Circuit Model for Black Hole Evaporation Abstract: In 1974, Stephen Hawking applied quantum field theory to the curved spacetime surrounding a black hole's event horizon and found that black holes evaporate, leading to the black hole information paradox. The currently accepted central dogma of black hole physics says that a black hole is nothing different than an ordinary quantum system from the outside point of view. A consequence is that black hole evaporation, like any other quantum process, should be unitary. In this talk, we will build a quantum circuit that describes this process and discuss compatibility of this fundamental quantum picture with the effective semiclassical picture and the conditions necessary for going in between the two pictures using our model.

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Willst du wirklich noch einen Sommer leiden?
by Epi Cooler 23 Apr '26

23 Apr '26

Keine Installation. Keine Techniker. Keine Ausreden. Hitze, Schweiß, schlaflose Nächte — alles kommt zurück. Wenn du jetzt nichts änderst. Epi Cooler Nur du und wirklich frische Luft. Opt Out

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No QIT seminar next week
by Ladina Hausmann 16 Apr '26

16 Apr '26

Hi all, Due to Sechseläuten, there is no QIT seminar next week. Best, Ladina

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Next weeks QIT seminar
by Ladina Hausmann 08 Apr '26

08 Apr '26

Hi all, Next week, Simon Fuchs will talk about “Classical physics as the coarse-grained limit of quantum mechanics”. See below for the abstract. The talk will take place on Monday at 15:00 in HIT K52. Best, Ladina %%%%%%%%%%%% Title: Classical physics as the coarse-grained limit of quantum mechanics Abstract: In this talk, I will discuss how classical behaviour emerges from quantum mechanics when observations are restricted to coarse-grained measurements. Building on earlier work at IQOQI, we argue that, when measurements cannot resolve the intrinsic spread of the wavefunction, coherence averages out and statistics appear classical. Such coarse measurements can be modeled by projections onto coherent states, an overcomplete basis that defines an effective phase space. Dynamically, the Ehrenfest theorem ensures approximate Newtonian trajectories, while decoherence suppresses corrections. Beyond kinematics and dynamics, this framework also hints at an emergent classical geometry, where phase-space distances correspond to the quantum distinguishability of coherent states. Finally, I will discuss extensions of this approach to relativistic systems. While it yields consistent, frame-dependent classicality conditions for massive particles, it encounters fundamental obstacles for massless ones due to the non-compact little group of lightlike momenta. This difficulty may help explain why classical massive objects are typically described as particles, whereas massless ones are treated as fields.

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No QIT seminar next week
by Ladina Hausmann 03 Apr '26

03 Apr '26

Hi all, Due to the Easter break, there will be no QIT seminar next week. Best, Ladina

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