Unraveling the switching dynamics in a quantum double-well potential

• URL: http://arxiv.org/abs/2501.00209v1
• Date: Tue, 31 Dec 2024 01:12:22 GMT
• Title: Unraveling the switching dynamics in a quantum double-well potential
• Authors: Qile Su, Rodrigo G. Cortiñas, Jayameenakshi Venkatraman, Shruti Puri,
• Abstract summary: We study the spontaneous switching of a quantum particle between the wells of a double-well potential. The switching rate exhibits a step-like decrease termed the "staircase" In addition, we show that in the regime of a few states in the well and under moderate to low temperatures, highly excited states are populated predominantly via cascaded and direct thermal heating.
• Score: 0.0
• License:
• Abstract: The spontaneous switching of a quantum particle between the wells of a double-well potential is a phenomenon of general interest to physics and chemistry. It was broadly believed that the switching rate decreases steadily with the size of the energy barrier. This view was challenged by a recent experiment on a driven superconducting Kerr nonlinear oscillator (often called the Kerr-cat qubit or the Kerr parametric oscillator), whose energy barrier can be increased by ramping up the drive. Remarkably, as the drive amplitude increases, the switching rate exhibits a step-like decrease termed the "staircase". The view challenged by the experiment demands a deep review of our understanding of quantum effects in double wells. In this work, we derive a semi-analytical formula for the switching rate that resolves a continuous transition between tunneling- and dissipation-dominated dynamics. These two dynamics are observed respectively in the flat and the steep parts of each step in the staircase. Our formula exposes two distinct dissipative processes that limit tunneling: dephasing and decay. This allows us to predict the critical drive amplitudes where steps occur. In addition, we show that in the regime of a few states in the well and under moderate to low temperatures, highly excited states are populated predominantly via cascaded and direct thermal heating rather than quantum heating. At very low temperatures, however, the perturbation induced by the nonhermitian Hamiltonian becomes important and facilitates a new form of quantum heating. We numerically map the activation mechanism as a function of drive amplitude, damping rate, and temperature. Our theory deepens the understanding of switching dynamics between metastable quantum states, highlights the importance of a general interplay between tunneling and dissipation, and identifies a novel quantum regime in activated transitions.

Related papers

• Oscillatory dissipative tunneling in an asymmetric double-well potential [32.65699367892846]
  Chemical research will benefit from a fully adjustable, asymmetric double-well equipped with precise measurement capabilities of the tunneling rates. We show a quantum simulator system that consists of a continuously driven Kerr parametric oscillator with a third order non-linearity that can be operated in the quantum regime to create a fully asymmetric double-well. Our work is a first step for the development of analog molecule simulators of proton transfer reactions based on quantum superconducting circuits.
  arXiv  Detail & Related papers  (2024-09-19T22:43:07Z)
• Nonlinear dynamical Casimir effect and Unruh entanglement in waveguide QED with parametrically modulated coupling [83.88591755871734]
  We study theoretically an array of two-level qubits moving relative to a one-dimensional waveguide. When the frequency of this motion approaches twice the qubit resonance frequency, it induces parametric generation of photons and excitation of the qubits. We develop a comprehensive general theoretical framework that incorporates both perturbative diagrammatic techniques and a rigorous master-equation approach.
  arXiv  Detail & Related papers  (2024-08-30T15:54:33Z)
• Quantum Tunnelling and Thermally Driven Transitions in a Double Well Potential at Finite Temperature [0.0]
  This paper aims to bridge gaps in understanding the crossover from thermal activation to quantum tunnelling. We study a Caldeira-Leggett-derived model of quantum Brownian motion and investigate the Lindblad and Schr"odinger dynamics numerically.
  arXiv  Detail & Related papers  (2023-12-19T12:25:22Z)
• Environment induced dynamical quantum phase transitions in two-qubit Rabi model [0.0]
  We observe dynamical quantum phase transitions in the dissipative two-qubit Rabi model. The transitions also manifest in two-qubit entanglement. These findings shed light on the complex behavior of dynamical quantum phase transitions in non-integrable models.
  arXiv  Detail & Related papers  (2023-12-09T22:30:23Z)
• Longitudinal (curvature) couplings of an $N$-level qudit to a superconducting resonator at the adiabatic limit and beyond [0.0]
  We investigate the coupling between a multi-level system, or qudit, and a superconducting (SC) resonator's electromagnetic field. For the first time, we derive Hamiltonians describing the longitudinal multi-level interactions in a general dispersive regime. We provide examples illustrating the transition from adiabatic to dispersive coupling in different qubit systems.
  arXiv  Detail & Related papers  (2023-12-05T20:33:59Z)
• Quantum field heat engine powered by phonon-photon interactions [58.720142291102135]
  We present a quantum heat engine based on a cavity with two oscillating mirrors. The engine performs an Otto cycle during which the walls and a field mode interact via a nonlinear Hamiltonian.
  arXiv  Detail & Related papers  (2023-05-10T20:27:15Z)
• Unconventional Quantum Electrodynamics with Hofstadter-Ladder Waveguide [5.693517450178467]
  We propose a novel quantum electrodynamics (QED) platform where quantum emitters interact with a Hofstadter-ladder waveguide. By assuming emitter's frequency to be resonant with the lower band, we find that the spontaneous emission is chiral. Due to quantum interference, we find that both the emitter-waveguide interaction and the amplitudes of bound states are periodically modulated by giant emitter's size.
  arXiv  Detail & Related papers  (2022-03-21T07:07:26Z)
• Intrinsic mechanisms for drive-dependent Purcell decay in superconducting quantum circuits [68.8204255655161]
  We find that in a wide range of settings, the cavity-qubit detuning controls whether a non-zero photonic population increases or decreases qubit decay Purcell. Our method combines insights from a Keldysh treatment of the system, and Lindblad theory.
  arXiv  Detail & Related papers  (2021-06-09T16:21:31Z)
• Bloch-Landau-Zener dynamics induced by a synthetic field in a photonic quantum walk [52.77024349608834]
  We realize a photonic quantum walk in the presence of a synthetic gauge field. We investigate intriguing system dynamics characterized by the interplay between Bloch oscillations and Landau-Zener transitions.
  arXiv  Detail & Related papers  (2020-11-11T16:35:41Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

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.