Three-outcome Bell inequalities tailored to many-body systems

Three-outcome Bell inequalities tailored to many-body systems

Date: 2025-05-06
Time: 12:15
Location: ICTQT, room 319
ICTQT Seminar
Speaker: Guillem Müller-Rigat (ICFO, Barcelona) Abstract We present a three-outcome Bell inequality which we show to be naturally suited to explore non- local correlations in many-body spin-1 systems or SU(3) models. From such an inequality, we show how simple bounds on single-particle observables can be used to construct Bell dimension witnesses, i.e., criteria whose violation […]

A Lightweight Protocol for Matchgate Fidelity Estimation

Date: 2025-03-22
Time: 12:15
Location: IFTiA room 361
ICTQT Seminar
Speaker: Jędrzej Burkat (Cavendish Laboratory, University of Cambridge) Abstract With the prospect of reaching hundreds of fault-tolerant qubits by the end of the decade, scaling up quantum computing infrastructure is as much of a theoretical as a practical challenge. Against the backdrop of progress in hardware, simple yet effective techniques are needed to address the […]

Quantum Secure Learning—Ensuring superior learning outcomes and data security for authorized learner

Date: 2025-03-19
Time: 14:00
Location: ICTQT room 45
ICTQT Seminar
Speaker: Jeongho Bang (Yonsei University, Korea) Abstract The learner's ability to generate a hypothesis that closely approximates the target function is crucial in machine learning. Achieving this requires sufficient data; however, unauthorized access by an eavesdropping learner can lead to security risks. Thus, it is important to ensure the performance of the "authorized" learner by […]

Arithmetic loophole in Bell’s theorem

Date: 2025-04-02
Time: 14:00
Location: ICTQT room 45
ICTQT Seminar
Speaker: Marek Czachor (Politechnika Gdańska) Abstract The talk is based on the following preprints: arXiv:2301.10727 Contra Bellum: Bell's theorem as a confusion of languages arXiv:2105.12728 Imitating quantum probabilities: Beyond Bell's theorem and Tsirelson bounds arXiv:2010.03366 Unifying Aspects of Generalized Calculus arXiv:2004.04097 Arithmetic loophole in Bell's theorem: An overlooked threat to entangled-state quantum cryptography

GKP-Based Photonic Quantum Computing: Challenges and Classical Simulation Approaches

Date: 2025-03-05
Time: 14:00
Location: ICTQT room 45
ICTQT Seminar
Speaker: Rajendra Bhati (Centrum Fizyki Teoretycznej, PAN) Abstract Gottesman-Kitaev-Preskill (GKP) states provide a promising route to fault-tolerant photonic quantum computing. In this talk, I will give a brief overview of GKP-based photonic quantum computing, highlighting its advantages and limitations. I will then discuss the challenges associated with classical simulations of multi-mode photonic systems and propose […]

Qubits, completeness, and contextuality: A new approach to foundations of quantum information

Date: 2025-02-05
Time: 14:00
Location: ICTQT room 45
ICTQT Seminar
Speaker: Jan-Åke Larsson (Linköping University) Abstract The usual explanation of the quantum computing speedup is parallel calculation, inserting a superposition of all possible input values into the computation. The picture painted is that the machine performs a calculation for every input, perhaps in multiple parallel worlds, and then combines the outcomes of each individual calculation […]

Operational approach to dimensionality and classicality in quantum theory

Date: 2025-01-15
Time: 14:00
Location: ICTQT room319
ICTQT Seminar
Speaker: Armin Tavakoli (Lund University) Abstract What is the dimension of a quantum ensemble? The standard answer is to count how many classical states are superposed, but that depends entirely on the reference frame of the observer. I discuss a different approach to the dimensionality of quantum systems which is independent of the frame in […]

Decoherence and entropy production due to quantum fluctuations of spacetime

Date: 2024-11-27
Time: 14:00
Location: ICTQT room 319
ICTQT Seminar
Speaker: Thiago H. Moreira Abstract The intersection between quantum mechanics and gravitational physics has been providing challenging puzzles for quite some time. In this presentation I discuss the dynamics of an open quantum system coupled with a bath of gravitons, the quanta of the gravitational field in the linear limit of general relativity. The focus […]

ETRI and experiments on long distance quantum communication

Date: 2024-11-08
Time: 12:15
Location: room 361 (IFTiA)
ICTQT Seminar
Speaker: Prof. Jungjin Ju Abstract Photonics is a key enabler for quantum systems, providing both core quantum functionality and the means by which quantum effects can be achieved, expressed, combined and utilized. In this talk, long distance quantum communications and silicon based photonic quantum process research activities of ETRI will be presented with short video introduction […]
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