Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1503.02591 · Physical Review Letters

Environment-Assisted Speed-up of the Field Evolution in Cavity Quantum Electrodynamics

Andres D. Cimmarusti, Zhihui Yan, Burkley D. Patterson, L. P. Corcos, Luis A. Orozco, Sebastian Deffner

Published Jun 11, 2015• 124 citations
arXivHTMLPDF

Abstract

We measure the quantum speed of the state evolution of the field in a weakly driven optical cavity QED system. To this end, the mode of the electromagnetic field is considered as a quantum system of interest with a preferential coupling to a tunable environment: the atoms. By controlling the environment, i.e., changing the number of atoms coupled to the optical cavity mode, an environment-assisted speed-up is realized: the quantum speed of the state repopulation in the optical cavity increases with the coupling strength between the optical cavity mode and this non-Markovian environment (the number of atoms).

DOI
10.1103/physrevlett.114.233602

Related papers

Information dynamics in cavity QED

Andrei N. Soklakov, Rüdiger Schack

A common experimental setup in cavity quantum electrodynamics consists of a single two-level atom interacting with a single mode of the electromagnetic field inside an optical cavity. The cavity is externally driven and the output is continuously monitored via homodyne measurements. We derive formulas for the optimal rates at which these measurements provide information about (i) the quantum state of the system composed of atom and electromagnetic field, and (ii) the coupling strength between atom and field. We find that the two information rates are anticorrelated.

arXiv:quant-ph/0210024•Physical Review A•Mar 13, 2003•0 citations

Quantum evolution speed in a double-layer environment

Kai Dong Xu, Guo‐Feng Zhang, Yue Ting Zhou +1 more

We investigate the dynamics of a two-level system in the presence of an overall environment composed of two layers. The first layer is just one single-mode cavity that decays to a memoryless reservoir while the second layer is two coupled single-mode cavities that decay to memoryless or memory-keeping reservoirs. We show that, in the weak-coupling regime between the qubit and the first-layer environment, the speed of evolution for the system can be controlled to a speeded-up or speeded-down process by manipulating the coupling strength in a double-layer environment. In particular, we find that multiple dynamics transitions from a not-speeded-up evolution to speeded-up evolution can be realized for the system by increasing the coupling strength in the second-layer environment. These results hold independently of the nature of the reservoirs in the second-layer environment.

Journal of the Optical Society of America B•Feb 7, 2020•2 citations

Classical-driving-assisted quantum speed-up

Ying-Jie Zhang, Wei Han, Yun‐Jie Xia +2 more

We propose a method of accelerating the speed of evolution of an open system by an external classical driving field for a qubit in a zero-temperature structured reservoir. It is shown that, with a judicious choice of the driving strength of the applied classical field, a speed-up evolution of an open system can be achieved in both the weak system-environment couplings and the strong system-environment couplings. By considering the relationship between non-Makovianity of environment and the classical field, we can drive the open system from the Markovian to the non-Markovian regime by manipulating the driving strength of the classical field. That is the intrinsic physical reason that the classical field may induce the speed-up process. In addition, the role of this classical field on the variation of quantum evolution speed in the whole decoherence process is discussed.

arXiv:1410.7106•Physical Review A•Mar 17, 2015•95 citations

Control protocols for manipulation of ground-state quantum beats in a cavity QED system

Andres D. Cimmarusti

Cavity quantum electrodynamics (QED) captures the essential interaction between two quantum systems, an atom (for example) and the quantized electromagnetic field. The cavity reduces the plethora of spatial modes of the field in free-space to one or two. This simplification facilitates the study and control of atom-light interactions. In this thesis we show results where we control both aspects of the interaction. Our first measurements demonstrate the implementation of a simple feedback mechanism on a two-mode cavity QED system to preserve the Zeeman coherence of a ground state superposition that generates quantum beats. Our investigation shows how to prevent a shift away from the Larmor frequency and associated decoherence caused by Rayleigh scattering. The protocol consists of turning off the drive of the system after the detection of a first photon and letting it evolve in the dark. Turning the drive back on after a pre set time reveals a phase accumulated only from Larmor precession, with the amplitude of the quantum beat more than a factor of two larger than with continuous drive. We present preliminary conditional measurements in a new cavity QED apparatus that show an environment-assisted speed-up of the evolution of our cavity photon state under weak driving. Changes in the number of atoms (N) that can couple to the field is our way of tailoring the environment. Our results indicate that as N increases, the rate of the re-population of the cavity photon state increases.

•Jan 1, 2014•0 citations

Controlling Speedup Induced by a Hierarchical Environment

Jing Wang, Yunan Wu, Wenyu Ji

Quantum speedup of an open quantum system can be induced by the non-Markovian effect of the environment. Although an environment with a higher degree of non-Markovianity may seem like it should cause a faster speed of quantum evolution, this seemingly intuitive thinking may not always be correct. To clarify this point, we give a mechanism for controlling speedup of a single qubit that is coupled to a hierarchical photonic-crystal (PC) environment, which contains a defect single-mode cavity and a semi-infinite one-dimensional (1D) waveguide. Via studying the dynamics of the qubit, we reveal that with a judicious choice of the qubit-cavity coupling strength and the memory time of the waveguide environment, a speed-up evolution can be achieved. In particular, we found that the quantum speedup is not entirely attributed to the non-Markovianity, but to the increase of the total amount of flow information. That is the intrinsic physical reason that the hierarchical environment may induce the speed-up process. Our results may open new perspectives for detecting quantum speedup in realistic environments.

Journal of Modern Physics•Jan 1, 2019•3 citations

Control of quantum dynamics: Non-Markovianity and the speedup of the open system evolution

Ying-Jie Zhang, Yun‐Jie Xia, Heng Fan

We illustrate a scheme for implementing a non-Markovian speedup evolution of an open system weakly interacting with a controllable environment: the coupled qubit-array. By controlling the environment, for instance by choosing a judicious nearest-neighbor excitation quanta hopping strength among the qubit-array or by changing the number of qubits coupled to the quantum system, two dynamical crossovers from Markovian to non-Markovian and from no-speedup to speedup are achieved in the weak system-environment coupling regime. For the weaker system-environment coupling, the larger hopping strength (or the larger qubits number) should be tuned to drive the non-Markovian speedup evolution. Particularly, the controllable non-Markovian dynamics is the intrinsic physical reason for the speedup evolution of a quantum system.

Europhysics Letters (EPL)•Nov 1, 2016•18 citations
We measure the quantum speed of the state evolution of the field in a weakly driven optical cavity QED system. To this end, the mode of the electromagnetic field is considered as a quantum system of interest with a preferential coupling to a tunable environment: the atoms. By controlling the environment, i.e., changing the number of atoms coupled to the optical cavity mode, an environment-assisted speed-up is realized: the quantum speed of the state repopulation in the optical cavity increases with the coupling strength between the optical cavity mode and this non-Markovian environment (the number of atoms).
A common experimental setup in cavity quantum electrodynamics consists of a single two-level atom interacting with a single mode of the electromagnetic field inside an optical cavity. The cavity is externally driven and the output is continuously monitored via homodyne measurements. We derive formulas for the optimal rates at which these measurements provide information about (i) the quantum state of the system composed of atom and electromagnetic field, and (ii) the coupling strength between atom and field. We find that the two information rates are anticorrelated.
We investigate the dynamics of a two-level system in the presence of an overall environment composed of two layers. The first layer is just one single-mode cavity that decays to a memoryless reservoir while the second layer is two coupled single-mode cavities that decay to memoryless or memory-keeping reservoirs. We show that, in the weak-coupling regime between the qubit and the first-layer environment, the speed of evolution for the system can be controlled to a speeded-up or speeded-down process by manipulating the coupling strength in a double-layer environment. In particular, we find that multiple dynamics transitions from a not-speeded-up evolution to speeded-up evolution can be realized for the system by increasing the coupling strength in the second-layer environment. These results hold independently of the nature of the reservoirs in the second-layer environment.
We propose a method of accelerating the speed of evolution of an open system by an external classical driving field for a qubit in a zero-temperature structured reservoir. It is shown that, with a judicious choice of the driving strength of the applied classical field, a speed-up evolution of an open system can be achieved in both the weak system-environment couplings and the strong system-environment couplings. By considering the relationship between non-Makovianity of environment and the classical field, we can drive the open system from the Markovian to the non-Markovian regime by manipulating the driving strength of the classical field. That is the intrinsic physical reason that the classical field may induce the speed-up process. In addition, the role of this classical field on the variation of quantum evolution speed in the whole decoherence process is discussed.
Cavity quantum electrodynamics (QED) captures the essential interaction between two quantum systems, an atom (for example) and the quantized electromagnetic field. The cavity reduces the plethora of spatial modes of the field in free-space to one or two. This simplification facilitates the study and control of atom-light interactions. In this thesis we show results where we control both aspects of the interaction. Our first measurements demonstrate the implementation of a simple feedback mechanism on a two-mode cavity QED system to preserve the Zeeman coherence of a ground state superposition that generates quantum beats. Our investigation shows how to prevent a shift away from the Larmor frequency and associated decoherence caused by Rayleigh scattering. The protocol consists of turning off the drive of the system after the detection of a first photon and letting it evolve in the dark. Turning the drive back on after a pre set time reveals a phase accumulated only from Larmor precession, with the amplitude of the quantum beat more than a factor of two larger than with continuous drive. We present preliminary conditional measurements in a new cavity QED apparatus that show an environment-assisted speed-up of the evolution of our cavity photon state under weak driving. Changes in the number of atoms (N) that can couple to the field is our way of tailoring the environment. Our results indicate that as N increases, the rate of the re-population of the cavity photon state increases.
Quantum speedup of an open quantum system can be induced by the non-Markovian effect of the environment. Although an environment with a higher degree of non-Markovianity may seem like it should cause a faster speed of quantum evolution, this seemingly intuitive thinking may not always be correct. To clarify this point, we give a mechanism for controlling speedup of a single qubit that is coupled to a hierarchical photonic-crystal (PC) environment, which contains a defect single-mode cavity and a semi-infinite one-dimensional (1D) waveguide. Via studying the dynamics of the qubit, we reveal that with a judicious choice of the qubit-cavity coupling strength and the memory time of the waveguide environment, a speed-up evolution can be achieved. In particular, we found that the quantum speedup is not entirely attributed to the non-Markovianity, but to the increase of the total amount of flow information. That is the intrinsic physical reason that the hierarchical environment may induce the speed-up process. Our results may open new perspectives for detecting quantum speedup in realistic environments.
We illustrate a scheme for implementing a non-Markovian speedup evolution of an open system weakly interacting with a controllable environment: the coupled qubit-array. By controlling the environment, for instance by choosing a judicious nearest-neighbor excitation quanta hopping strength among the qubit-array or by changing the number of qubits coupled to the quantum system, two dynamical crossovers from Markovian to non-Markovian and from no-speedup to speedup are achieved in the weak system-environment coupling regime. For the weaker system-environment coupling, the larger hopping strength (or the larger qubits number) should be tuned to drive the non-Markovian speedup evolution. Particularly, the controllable non-Markovian dynamics is the intrinsic physical reason for the speedup evolution of a quantum system.