Initial-state-dependent quantum speed limit for dissipative state preparation: Framework and optimization

• URL: http://arxiv.org/abs/2303.12967v2
• Date: Fri, 24 Mar 2023 05:03:44 GMT
• Title: Initial-state-dependent quantum speed limit for dissipative state preparation: Framework and optimization
• Authors: Junjie Liu and Hanlin Nie
• Abstract summary: We focus on a Markovian dissipative state preparation scheme where the prepared state is one of the energy eigenstates. We derive an initial-state-dependent quantum speed limit (QSL) that offers a more refined measure of the actual evolution time. We demonstrate the effectiveness of our strategy in a dissipative Rydberg atom system for preparing the Bell state.
• Score: 6.211723927647019
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Dissipation has traditionally been considered a hindrance to quantum information processing, but recent studies have shown that it can be harnessed to generate desired quantum states. To be useful for practical applications, the ability to speed up the dissipative evolution is crucial. In this study, we focus on a Markovian dissipative state preparation scheme where the prepared state is one of the energy eigenstates. We derive an initial-state-dependent quantum speed limit (QSL) that offers a more refined measure of the actual evolution time compared to the commonly used initial-state-independent relaxation time. This allows for a passive optimization of dissipative evolution across different initial states. By minimizing the dissipated heat during the preparation process, conditioned on the minimization of evolution time using the QSL, we find that the preferred initial state has a specific permutation of diagonal elements with respect to an ordered energy eigenbasis of increasing eigenvalues. In this configuration, the population on the prepared state is the largest, and the remaining diagonal elements are sorted in an order resembling that of a passive state in the same ordered energy eigenbasis. We demonstrate the effectiveness of our strategy in a dissipative Rydberg atom system for preparing the Bell state. Our work provides new insights into the optimization of dissipative state preparation processes and could have significant implications for practical quantum technologies.

Related papers

• Thermalization and Criticality on an Analog-Digital Quantum Simulator [133.58336306417294]
  We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions. We digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization.
  arXiv  Detail & Related papers  (2024-05-27T17:40:39Z)
• Exponential optimization of quantum state preparation via adiabatic thermalization [0.0]
  We study the preparation of a given quantum state on a quantum computing register. We use the adiabatic theorem for state preparation, whose error decreases exponentially as a function of the thermalization time. We then design a preconditioning term that modifies the adiabatic preparation, thus reducing its characteristic time.
  arXiv  Detail & Related papers  (2024-05-06T17:29:31Z)
• Initial state preparation for quantum chemistry on quantum computers [1.4336086085916357]
  Quantum algorithms for ground-state energy estimation of chemical systems require a high-quality initial state. We address the initial state preparation problem with an end-to-end algorithm that prepares and quantifies the quality of initial states. We show how the energy distribution can help in identifying potential quantum advantage.
  arXiv  Detail & Related papers  (2023-10-27T18:00:59Z)
• Adiabatic quantum imaginary time evolution [0.0]
  We introduce an adiabatic state preparation protocol which implements quantum imaginary time evolution under the Hamiltonian of the system. Unlike the original quantum imaginary time evolution algorithm, adiabatic quantum imaginary time evolution does not require quantum state tomography during its runtime.
  arXiv  Detail & Related papers  (2023-08-07T04:27:30Z)
• Projection algorithm for state preparation on quantum computers [0.0]
  We present an efficient method to prepare states of a many-body system on quantum hardware. We first isolate individual quantum numbers and then using time evolution to isolate the energy. The total time evolved for an accurate solution is proportional to the ratio of the spectrum range of the trial state to the gap to the lowest excited state.
  arXiv  Detail & Related papers  (2022-11-19T00:19:55Z)
• A Quantum Optimal Control Problem with State Constrained Preserving Coherence [68.8204255655161]
  We consider a three-level $Lambda$-type atom subjected to Markovian decoherence characterized by non-unital decoherence channels. We formulate the quantum optimal control problem with state constraints where the decoherence level remains within a pre-defined bound.
  arXiv  Detail & Related papers  (2022-03-24T21:31:34Z)
• Maximum entropy quantum state distributions [58.720142291102135]
  We go beyond traditional thermodynamics and condition on the full distribution of the conserved quantities. The result are quantum state distributions whose deviations from thermal states' get more pronounced in the limit of wide input distributions.
  arXiv  Detail & Related papers  (2022-03-23T17:42:34Z)
• Bridging the Gap Between the Transient and the Steady State of a Nonequilibrium Quantum System [58.720142291102135]
  Many-body quantum systems in nonequilibrium remain one of the frontiers of many-body physics. Recent work on strongly correlated electrons in DC electric fields illustrated that the system may evolve through successive quasi-thermal states. We demonstrate an extrapolation scheme that uses the short-time transient calculation to obtain the retarded quantities.
  arXiv  Detail & Related papers  (2021-01-04T06:23:01Z)
• Quantum speed limits for time evolution of a system subspace [77.34726150561087]
  In the present work, we are concerned not with a single state but with a whole (possibly infinite-dimensional) subspace of the system states that are subject to the Schroedinger evolution. We derive an optimal estimate on the speed of such a subspace evolution that may be viewed as a natural generalization of the Fleming bound.
  arXiv  Detail & Related papers  (2020-11-05T12:13:18Z)
• Benchmarking adaptive variational quantum eigensolvers [63.277656713454284]
  We benchmark the accuracy of VQE and ADAPT-VQE to calculate the electronic ground states and potential energy curves. We find both methods provide good estimates of the energy and ground state. gradient-based optimization is more economical and delivers superior performance than analogous simulations carried out with gradient-frees.
  arXiv  Detail & Related papers  (2020-11-02T19:52:04Z)
• Initial-State Dependence of Thermodynamic Dissipation for any Quantum Process [0.0]
  We show new exact results about the nonequilibrium thermodynamics of open quantum systems at arbitrary timescales. For any finite-time process with a fixed initial environment, we show that the contraction of the system's distinction exactly quantifies its thermodynamic dissipation.
  arXiv  Detail & Related papers  (2020-02-26T12:10:10Z)

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.