Ergodiscord: An Operational and Distinct Notion of Quantumness of Correlations

• URL: http://arxiv.org/abs/2407.08292v3
• Date: Thu, 08 May 2025 12:09:17 GMT
• Title: Ergodiscord: An Operational and Distinct Notion of Quantumness of Correlations
• Authors: Mir Alimuddin, Snehasish Roy Chowdhury, Ram Krishna Patra, Subhendu B. Ghosh, Tommaso Tufarelli, Gerardo Adesso, Manik Banik,
• Abstract summary: We present a framework for exploring quantumness of correlations in multipartite quantum states.<n>We introduce an operational quantifier of nonclassicality, termed em ergodiscord.<n>We show that a mixed nonclassical state can lock more work than the maximally entangled state of the corresponding system.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Nonclassicality in composite quantum systems depicts several puzzling manifestations, with Einstein-Podolsky-Rosen entanglement, Schr\"odinger steering, and Bell nonlocality being the most celebrated ones. In addition to those, an unentangled quantum state can also exhibit nonclassicality, as evidenced from notions such as quantum discord and work deficit. In this work, we present a general framework for exploring quantumness of correlations in multipartite quantum states. By exploiting the different signatures reflected on observable quantities depending on whether subsystems of a composite systems are probed jointly or independently, we introduce an operational quantifier of nonclassicality, termed {\em ergodiscord}. As we show, this newly proposed quantifier faithfully captures nonclassicality in any bipartite quantum state, while being fundamentally distinct from the original quantum discord. Moreover, ergodiscord uncovers an intriguing phenomenon called `nonlocal energy locking', where a useful form of energy (i.e. work) gets locked in correlations of nonclassical states. We also show that a mixed nonclassical state can lock more work than the maximally entangled state of the corresponding system, establishing an interesting super-additivity phenomenon of nonlocal energy locking. The present work may inspire novel designs of quantum energy storage devices by utilizing nonclassical correlations in composite quantum systems.

Related papers

• Observation of Quantum Darwinism and the Origin of Classicality with Superconducting Circuits [9.09683951826704]
  How can we rationalize everyday classical observations from an inherently quantum world?<n>Quantum Darwinism offers a compelling framework to explain this emergence of classicality.<n>We observe the highly structured branching quantum states that support classicality and the saturation of quantum mutual information.
  arXiv  Detail & Related papers  (2025-04-01T13:33:32Z)
• Operationally classical simulation of quantum states [41.94295877935867]
  A classical state-preparation device cannot generate superpositions and hence its emitted states must commute. We show that no such simulation exists, thereby certifying quantum coherence. Our approach is a possible avenue to understand how and to what extent quantum states defy generic models based on classical devices.
  arXiv  Detail & Related papers  (2025-02-03T15:25:03Z)
• Kochen-Specker for many qubits and the classical limit [55.2480439325792]
  It is shown that quantum and classical predictions converge as the number of qubits is increases to the macroscopic scale. This way to explain the classical limit concurs with, and improves, a result previously reported for GHZ states.
  arXiv  Detail & Related papers  (2024-11-26T22:30:58Z)
• Precision bounds for multiple currents in open quantum systems [37.69303106863453]
  We derivation quantum TURs and KURs for multiple observables in open quantum systems undergoing Markovian dynamics. Our bounds are tighter than previously derived quantum TURs and KURs for single observables. We also find an intriguing quantum signature of correlations captured by the off-diagonal element of the Fisher information matrix.
  arXiv  Detail & Related papers  (2024-11-13T23:38:24Z)
• Efficient Quantum Pseudorandomness from Hamiltonian Phase States [41.94295877935867]
  We introduce a quantum hardness assumption called the Hamiltonian Phase State (HPS) problem.<n>We show that our assumption is plausibly fully quantum; meaning, it cannot be used to construct one-way functions.<n>We show that our assumption and its variants allow us to efficiently construct many pseudorandom quantum primitives.
  arXiv  Detail & Related papers  (2024-10-10T16:10:10Z)
• The role of non-classicality in mediated spatial quantum correlations [0.0]
  The study of non-classicality is essential to understand the quantum-to-classical transition in physical systems. We propose a new inequality that quantitatively links the increase in quantum correlations between the probes to the degree of non-commutativity of the mediator's observables.
  arXiv  Detail & Related papers  (2024-10-01T16:07:04Z)
• Quantum information with quantum-like bits [0.0]
  We show how arbitrary gates can be implemented by manipulating many-body correlations.<n>This suggests the possibility of quantum-like information processing on a special class of many-body classical systems.
  arXiv  Detail & Related papers  (2024-08-12T20:40:54Z)
• Breakdown of the Quantum Distinction of Regular and Chaotic Classical Dynamics in Dissipative Systems [0.0]
  In an isolated system, quantum chaos refers to properties of the spectrum that emerge when the classical counterpart of the system is chaotic. We show that the onset of cubic level repulsion in the open quantum model is not always related with chaotic structures in the classical limit.
  arXiv  Detail & Related papers  (2024-06-11T18:00:03Z)
• Causal Data Fusion with Quantum Confounders [0.8437187555622164]
  We show quantum experiments can generate observational and interventional data with a non-classical signature when pieced together that cannot be reproduced classically. We show that non-classicality genuine to the fusion of multiple data tables is achievable with quantum resources. Our work shows incorporating interventions can be a powerful tool to detect non-classicality beyond the violation of a standard Bell inequality.
  arXiv  Detail & Related papers  (2024-05-29T17:10:30Z)
• Quantum Non-classicality from Causal Data Fusion [0.8437187555622164]
  Bell's theorem shows that quantum correlations are incompatible with a classical theory of cause and effect. We investigate the problem of causal data fusion that aims to piece together data tables collected under heterogeneous conditions. We demonstrate the existence of quantum non-classicality resulting from data fusion, even in scenarios where achieving standard Bell non-classicality is impossible.
  arXiv  Detail & Related papers  (2024-05-29T16:35:59Z)
• Generating quantum dissonance via local operations [0.0]
  Quantum dissonance refers to how quantum discord appears as a non-classical correlation in a system without entanglement. We propose two explicit procedures for obtaining separable Werner states, a type of mixed state with nonzero QD.
  arXiv  Detail & Related papers  (2024-05-14T13:02:05Z)
• A computational test of quantum contextuality, and even simpler proofs of quantumness [43.25018099464869]
  We show that an arbitrary contextuality game can be compiled into an operational "test of contextuality" involving a single quantum device. Our work can be seen as using cryptography to enforce spatial separation within subsystems of a single quantum device.
  arXiv  Detail & Related papers  (2024-05-10T19:30:23Z)
• Quantitative bounds to propagation of quantum correlations in many-body systems [0.0]
  We establish limits to bipartite quantum correlations in many-body systems. Results confirm that proliferation of classical information in the Universe suppresses quantum correlations.
  arXiv  Detail & Related papers  (2023-10-04T00:24:06Z)
• Persisting quantum effects in the anisotropic Rabi model at thermal equilibrium [0.0]
  We study the long-lived quantum correlations and nonclassical states generated in the anisotropic Rabi model. We demonstrate a stark distinction between virtual excitations produced beyond the strong coupling regime and the quantumness quantifiers once the light-matter interaction has been switched off.
  arXiv  Detail & Related papers  (2023-09-05T10:59:32Z)
• Classical Verification of Quantum Learning [42.362388367152256]
  We develop a framework for classical verification of quantum learning. We propose a new quantum data access model that we call "mixture-of-superpositions" quantum examples. Our results demonstrate that the potential power of quantum data for learning tasks, while not unlimited, can be utilized by classical agents.
  arXiv  Detail & Related papers  (2023-06-08T00:31:27Z)
• Robustness of non-locality in many-body open quantum systems [0.0]
  Non-locality consists in the existence of non-classical correlations between local measurements. We show that non-local correlations are present, can be detected and might be robust against noise in many-body open quantum systems.
  arXiv  Detail & Related papers  (2022-02-24T13:05:36Z)
• 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)
• Creating and destroying coherence with quantum channels [62.997667081978825]
  We study optimal ways to create a large amount of quantum coherence via quantum channels. correlations in multipartite systems do not enhance the ability of a quantum channel to create coherence. We show that a channel can destroy more coherence when acting on a subsystem of a bipartite state.
  arXiv  Detail & Related papers  (2021-05-25T16:44:13Z)
• Quantum Causal Inference in the Presence of Hidden Common Causes: an Entropic Approach [34.77250498401055]
  We put forth a new theoretical framework for merging quantum information science and causal inference by exploiting entropic principles. We apply our proposed framework to an experimentally relevant scenario of identifying message senders on quantum noisy links. This approach can lay the foundations of identifying originators of malicious activity on future multi-node quantum networks.
  arXiv  Detail & Related papers  (2021-04-24T22:45:50Z)
• Non-equilibrium stationary states of quantum non-Hermitian lattice models [68.8204255655161]
  We show how generic non-Hermitian tight-binding lattice models can be realized in an unconditional, quantum-mechanically consistent manner. We focus on the quantum steady states of such models for both fermionic and bosonic systems.
  arXiv  Detail & Related papers  (2021-03-02T18:56:44Z)

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.