Theory-independent monitoring of the decoherence of a superconducting qubit with generalized contextuality

• URL: http://arxiv.org/abs/2411.13421v1
• Date: Wed, 20 Nov 2024 16:06:52 GMT
• Title: Theory-independent monitoring of the decoherence of a superconducting qubit with generalized contextuality
• Authors: Albert Aloy, Matteo Fadel, Thomas D. Galley, Caroline L. Jones, Markus P. Mueller,
• Abstract summary: Characterizing the nonclassicality of quantum systems under minimal assumptions is an important challenge for quantum foundations and technology. We introduce a theory-independent method of process tomography and perform it on a superconducting qubit. We demonstrate its decoherence without assuming quantum theory or trusting the devices by modelling the system as a general probabilistic theory.
• Score: 0.0
• License:
• Abstract: Characterizing the nonclassicality of quantum systems under minimal assumptions is an important challenge for quantum foundations and technology. Here we introduce a theory-independent method of process tomography and perform it on a superconducting qubit. We demonstrate its decoherence without assuming quantum theory or trusting the devices by modelling the system as a general probabilistic theory. We show that the superconducting system is initially well-described as a quantum bit, but that its realized state space contracts over time, which in quantum terminology indicates its loss of coherence. The system is initially nonclassical in the sense of generalized contextuality: it does not admit of a hidden-variable model where statistically indistinguishable preparations are represented by identical hidden-variable distributions. In finite time, the system becomes noncontextual and hence loses its nonclassicality. Moreover, we demonstrate in a theory-independent way that the system undergoes non-Markovian evolution at late times. Our results extend theory-independent tomography to time-evolving systems, and show how important dynamical physical phenomena can be experimentally monitored without assuming quantum theory.

Related papers

• A Theory of Quantum Jumps [44.99833362998488]
  We study fluorescence and the phenomenon of quantum jumps'' in idealized models of atoms coupled to the quantized electromagnetic field. Our results amount to a derivation of the fundamental randomness in the quantum-mechanical description of microscopic systems.
  arXiv  Detail & Related papers  (2024-04-16T11:00:46Z)
• A Quantum Theory with Non-collapsing Measurements [0.0]
  A collapse-free version of quantum theory is introduced to study the role of the projection postulate. We assume "passive" measurements that do not update quantum states while measurement outcomes still occur probabilistically. The resulting quantum-like theory has only one type of dynamics, namely unitary evolution.
  arXiv  Detail & Related papers  (2023-03-23T16:32:29Z)
• Demonstrating Quantum Microscopic Reversibility Using Coherent States of Light [58.8645797643406]
  We propose and experimentally test a quantum generalization of the microscopic reversibility when a quantum system interacts with a heat bath. We verify that the quantum modification for the principle of microscopic reversibility is critical in the low-temperature limit.
  arXiv  Detail & Related papers  (2022-05-26T00:25:29Z)
• Redundantly amplified information suppresses quantum correlations in many-body systems [0.0]
  We show that independent agents who monitor environment fragments can eavesdrop only on amplified and redundantly disseminated information. We also show that the emergence of classical objectivity is signaled by a distinctive scaling of the conditional mutual information.
  arXiv  Detail & Related papers  (2022-02-18T17:43:16Z)
• Testing quantum theory by generalizing noncontextuality [0.0]
  We prove that only Jordan-algebraic state spaces are exactly embeddable into quantum theory. We propose an experimental test of quantum theory by probing single physical systems.
  arXiv  Detail & Related papers  (2021-12-17T19:00:24Z)
• Sensing quantum chaos through the non-unitary geometric phase [62.997667081978825]
  We propose a decoherent mechanism for sensing quantum chaos. The chaotic nature of a many-body quantum system is sensed by studying the implications that the system produces in the long-time dynamics of a probe coupled to it.
  arXiv  Detail & Related papers  (2021-04-13T17:24:08Z)
• 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)
• The Montevideo Interpretation: How the inclusion of a Quantum Gravitational Notion of Time Solves the Measurement Problem [0.0]
  We review the Montevideo Interpretation of quantum mechanics, based on the use of real clocks to describe physics. Recent results on quantum complexity provide additional support to the type of global protocols used to prove that within ordinary -- unitary -- quantum mechanics no definite event occurs. We show that, if one takes into account fundamental inescapable uncertainties in measuring length and time intervals due to general relativity and quantum mechanics, the previously mentioned global protocols no longer allow to distinguish whether the state is in a superposition or not.
  arXiv  Detail & Related papers  (2020-10-27T18:00:01Z)
• From a quantum theory to a classical one [117.44028458220427]
  We present and discuss a formal approach for describing the quantum to classical crossover. The method was originally introduced by L. Yaffe in 1982 for tackling large-$N$ quantum field theories.
  arXiv  Detail & Related papers  (2020-04-01T09:16:38Z)
• Witnessing non-classicality beyond quantum theory [0.0]
  We show that if a physical system can mediate locally the generation of entanglement between two quantum systems, then it itself must be non-classical. We do not assume any classical or quantum formalism to describe the mediating physical system.
  arXiv  Detail & Related papers  (2020-03-17T22:42:42Z)
• Entropic Uncertainty Relations and the Quantum-to-Classical transition [77.34726150561087]
  We aim to shed some light on the quantum-to-classical transition as seen through the analysis of uncertainty relations. We employ entropic uncertainty relations to show that it is only by the inclusion of imprecision in our model of macroscopic measurements that we can prepare a system with two simultaneously well-defined quantities.
  arXiv  Detail & Related papers  (2020-03-04T14:01:17Z)

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.