ITP-quantumseminare

itp-quantumseminare@lists.phys.ethz.ch

November 2026

1 participants
2 discussions

Next weeks QIT seminars
by Ladina Hausmann 07 Nov '26

07 Nov '26

Hi all, Next week we will have two talks: (1) On Tuesday at 11:00 Tim Palmer will talk about “Rational Quantum Mechanics: Testing Quantum Theory with Quantum Computers”. The talk will take place in HIL E 9. (2) On Friday at 14:00 Sadra Boreiri will talk about “Fermions are fundamentally more nonlocal than Bosons”. The talk will take place in HIT E 41.1. See below for the abstracts. Best, Ladina %%%%%%% Title: Rational Quantum Mechanics: Testing Quantum Theory with Quantum Computers Abstract: Rational Quantum Mechanics (RaQM) is novel theory of quantum physics based on a specific discretisation of the Riemann Sphere of complex numbers. Applied to complex Hilbert Space, this theory predicts that quantum states only have beable representations in bases where squared amplitudes and complex phases are rational numbers. It is proposed that gravity determines the fineness of this discretisation of Hilbert Space. RaQM is a simpler theory than QM (e.g. Born’s Rule is emergent) and the violation of Bell’s inequality can be explained without spooky action at a distance. An experiment is proposed to test RaQM: the exponential advantage of algorithms that use the Quantum Fourier Transform will fail in quantum computers that use more than about 400 qubits. RaQM suggests that gravity is not something we quantise, it is something already hard baked into the formalism of basic quantum physics - it’s just we don’t see this when we use QM in its continuum limit. Reference: https://www.pnas.org/doi/10.1073/pnas.2523350123 %%% Title: Fermions are fundamentally more nonlocal than Bosons Abstract: Bell’s theorem establishes that entangled quantum particles can generate correlations that classical particles cannot reproduce without additional nonlocal resources, such as communication. In this sense, quantum particles are fundamentally more nonlocal than classical ones, making entanglement an unavoidable ingredient of physics. In this talk, I will present an analogous result within quantum theory itself. We show that indistinguishable fermions distributed through a quantum network can generate correlations that neither distinguishable particles nor indistinguishable bosons can reproduce without additional communication. To demonstrate this separation, we introduce a distributed rewiring game in which distant parties locally prepare, exchange, and measure quantum particles without knowing the global network configuration. The separation arises from the fermionic exchange sign, which generates correlations that cannot be reproduced by standard local qubit or bosonic protocols. In this operational sense, fermions are fundamentally more nonlocal than bosons and distinguishable particles, making fermionic anticommutation and indistinguishability unavoidable operational resources. Our result can also be viewed from a quantum information processing perspective: fermions can outperform all qubit-based protocols in certain distributed computing tasks under the same locality constraints. This demonstrates the potential of fermionic information carriers, or febits, as resources for quantum information processing beyond the conventional qubit framework. Reference: https://arxiv.org/abs/2606.12363

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No QIT seminar next week
by Ladina Hausmann 01 Nov '26

01 Nov '26

Hi all, There is no QIT seminar planned for next week. Best, Ladina

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