Semi-device-independently characterizing quantum temporal correlations

• URL: http://arxiv.org/abs/2305.19548v3
• Date: Tue, 2 Jul 2024 07:39:09 GMT
• Title: Semi-device-independently characterizing quantum temporal correlations
• Authors: Shin-Liang Chen, Jens Eisert,
• Abstract summary: We develop a framework for characterizing quantum temporal correlations in a general temporal scenario. Our framework serves as a natural tool for quantum certification in a temporal scenario. We present a number of applications, including bounding the maximal violation of temporal Bell inequalities.
• Score: 0.3683202928838613
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We develop a framework for characterizing quantum temporal correlations in a general temporal scenario, in which an initial quantum state is measured, sent through a quantum channel, and finally measured again. This framework does not make any assumptions on the system nor on the measurements, namely, it is device-independent. It is versatile enough, however, to allow for the addition of further constraints in a semi-device-independent setting. Our framework serves as a natural tool for quantum certification in a temporal scenario when the quantum devices involved are uncharacterized or partially characterized. It can hence also be used for characterizing quantum temporal correlations when one assumes an additional constraint of no-signalling in time, there are upper bounds on the involved systems' dimensions, rank constraints -- for which we prove genuine quantum separations over local hidden variable models -- or further linear constraints. We present a number of applications, including bounding the maximal violation of temporal Bell inequalities, quantifying temporal steerability, bounding the maximum successful probability in quantum randomness access codes.

Related papers

• Stochastic resetting in discrete-time quantum dynamics: steady states and correlations in few-qubit systems [0.0]
  We investigate the steady-state properties of discrete-time reset dynamics on quantum computers. For Poissonian resets, we compute the stationary state of the process and demonstrate the existence of "resonances" in the quantum gates. We show that, when the reset probability vanishes sufficiently rapidly with time, the system does not approach a steady state.
  arXiv  Detail & Related papers  (2024-10-15T11:07:25Z)
• Quantum speed limit for Kirkwood-Dirac quasiprobabilities [0.0]
  We derive quantum speed limits for two-time correlation functions arising from statistics of measurements. Our quantum speed limits are derived from the Heisenberg-Robertson uncertainty relation, and set the minimal time at which a quasiprobability can become non-positive. As an illustrative example, we apply these results to a conditional quantum gate, by determining the optimal condition giving rise to non-classicality at maximum speed.
  arXiv  Detail & Related papers  (2024-02-12T11:28:56Z)
• Qubit-environment entanglement in time-dependent pure dephasing [0.0]
  We show that the methods for quantifying system-environment entanglement can be straightforwardly generalized to time-dependent Hamiltonians. We use these methods to study the nature of the decoherence of a qubit-oscillator system.
  arXiv  Detail & Related papers  (2023-12-05T11:23:25Z)
• Prolonging a discrete time crystal by quantum-classical feedback [0.0]
  We propose a timeperiodic scheme that leverages quantum-classical feedback protocols in subregions of the system to enhance a time crystal signal significantly exceeding the decoherence time of the device. Based on classical simulation quantum circuit realizations, we find that this approach is suitable for implementation on existing quantum phases and hardware.
  arXiv  Detail & Related papers  (2023-09-05T11:43:26Z)
• Quantum Conformal Prediction for Reliable Uncertainty Quantification in Quantum Machine Learning [47.991114317813555]
  Quantum models implement implicit probabilistic predictors that produce multiple random decisions for each input through measurement shots. This paper proposes to leverage such randomness to define prediction sets for both classification and regression that provably capture the uncertainty of the model.
  arXiv  Detail & Related papers  (2023-04-06T22:05:21Z)
• Universality of critical dynamics with finite entanglement [68.8204255655161]
  We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement. Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
  arXiv  Detail & Related papers  (2023-01-23T19:23:54Z)
• Critical Quantum Metrology with Fully-Connected Models: From Heisenberg to Kibble-Zurek Scaling [0.0]
  Phase transitions represent a compelling tool for classical and quantum sensing applications. Quantum sensors can saturate the Heisenberg scaling in the limit of large probe number and long measurement time. Our analysis unveils the existence of universal precision-scaling regimes.
  arXiv  Detail & Related papers  (2021-10-08T14:11:54Z)
• Experimental violations of Leggett-Garg's inequalities on a quantum computer [77.34726150561087]
  We experimentally observe the violations of Leggett-Garg-Bell's inequalities on single and multi-qubit systems. Our analysis highlights the limits of nowadays quantum platforms, showing that the above-mentioned correlation functions deviate from theoretical prediction as the number of qubits and the depth of the circuit grow.
  arXiv  Detail & Related papers  (2021-09-06T14:35:15Z)
• Preparing random states and benchmarking with many-body quantum chaos [48.044162981804526]
  We show how to predict and experimentally observe the emergence of random state ensembles naturally under time-independent Hamiltonian dynamics. The observed random ensembles emerge from projective measurements and are intimately linked to universal correlations built up between subsystems of a larger quantum system. Our work has implications for understanding randomness in quantum dynamics, and enables applications of this concept in a wider context.
  arXiv  Detail & Related papers  (2021-03-05T08:32:43Z)
• Direct Quantum Communications in the Presence of Realistic Noisy Entanglement [69.25543534545538]
  We propose a novel quantum communication scheme relying on realistic noisy pre-shared entanglement. Our performance analysis shows that the proposed scheme offers competitive QBER, yield, and goodput.
  arXiv  Detail & Related papers  (2020-12-22T13:06:12Z)
• The role of boundary conditions in quantum computations of scattering observables [58.720142291102135]
  Quantum computing may offer the opportunity to simulate strongly-interacting field theories, such as quantum chromodynamics, with physical time evolution. As with present-day calculations, quantum computation strategies still require the restriction to a finite system size. We quantify the volume effects for various $1+1$D Minkowski-signature quantities and show that these can be a significant source of systematic uncertainty.
  arXiv  Detail & Related papers  (2020-07-01T17:43:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.