© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:atom-ph/9601004 · Physical Review A

Dynamics, correlations, and phases of the micromaser

Per Elmfors, Benny E. Lautrup, Bo-Sture Skagerstam

Published Dec 1, 1996• 14 citations

Abstract

The micromaser possesses a variety of dynamical phase transitions parametrized by the flux of atoms and the time of flight of the atom within the cavity. We discuss how these phases may be revealed to an observer outside the cavity using the long-time correlation length in the atomic beam. Some of the phase transitions are not reflected in the average excitation level of the outgoing atom, which is the commonly used observable. The correlation length is directly related to the leading eigenvalue of the time evolution operator, which we study in order to elucidate the phase structure. We find that as a function of the time of flight the transition from the thermal to the maser phase is characterized by a sharp peak in the correlation length. For longer times of flight there is a transition to a phase where the correlation length grows exponentially with the flux. We present a detailed numerical and analytical treatment of the different phases and discuss the physics behind them. \textcopyright{} 1996 The American Physical Society.

DOI: 10.1103/physreva.54.5171

Related papers

Atomic beam correlations and the quantum state of the micromaser

Per Elmfors, Benny E. Lautrup, Bo-Sture Skagerstam

Correlation measurements on the states of two-level atoms having passed through a micromaser at different times can be used to infer properties of the quantum state of the radiation field in the cavity. Long(short) correlation length in time is to some extent associated with super(sub)-Poissonian photon statistics. The correlation length is also an indicator of a phase structure much richer than what is revealed by the usual single-time observables, like the atomic inversion or the Mandel quality factor. In realistic experimental situations the correlations may extend over many times the decay time of the cavity. Our assertions are verified by comparing theoretical calculations with a high-precision Monte-Carlo simulation of the micromaser system.

arXiv:cond-mat/9506058•Physica Scripta•Jun 1, 1997•5 citations

Theory of the Microscopic Maser Phase Transitions

Per Kristian Rekdal, Bo-Sture Skagerstam

Phase diagrams of the micromaser system are mapped out in terms of the physical parameters at hand like the atom cavity transit time, the atom-photon frequency detuning, the number of thermal photons and the probability for a pump atom to be in its excited state. Critical fluctuations are studied in terms of correlation measurements on atoms having passed through the micromaser or on the microcavity photons themselves. At sufficiently large values of the detuning we find a ``twinkling'' mode of the micromaser system. Detailed properties of the trapping states are also presented.

arXiv:quant-ph/0003133•Mar 29, 2000•0 citations

Quantum trajectory phase transitions in the micromaser

Juan P. Garrahan, Andrew D. Armour, Igor Lesanovsky

We study the dynamics of the single-atom maser, or micromaser, by means of the recently introduced method of thermodynamics of quantum jump trajectories. We find that the dynamics of the micromaser displays multiple space-time phase transitions, i.e., phase transitions in ensembles of quantum jump trajectories. This rich dynamical phase structure becomes apparent when trajectories are classified by dynamical observables that quantify dynamical activity, such as the number of atoms that have changed state while traversing the cavity. The space-time transitions can be either first order or continuous, and are controlled not just by standard parameters of the micromaser but also by nonequilibrium "counting" fields. We discuss how the dynamical phase behavior relates to the better known stationary-state properties of the micromaser.

arXiv:1103.0919•Physical Review E•Aug 8, 2011•59 citations

Noise and Order in Cavity Quantum Electrodynamics

Rekdal, Per K., Skagerstam, Bo-Sture K.

In this paper we investigate the various aspects of noise and order in the micromaser system. In particular, we study the effect of adding fluctuations to the atom cavity transit time or to the atom-photon frequency detuning. By including such noise-producing mechanisms we study the probability and the joint probability for excited atoms to leave the cavity. The influence of such fluctuations on the phase structure of the micromaser as well as on the long-time atom correlation length is also discussed. We also derive the asymptotic form of micromaser observables.

•Apr 2, 2001•2 citations

Collective two-atom effects and trapping states in the micromaser

Per Kristian Rekdal, Bo-Sture Skagerstam

We investigate signals of trapping states in the micromaser system in terms of the average number $⟨n⟩$ of cavity photons as well as a suitably defined correlation length of atoms leaving the cavity. In the description of collective two-atom effects we allow the mean number, $ϵ$, of pump atoms inside the cavity during the characteristic atomic cavity transit time to be as large as of order one. The master equation we consider, which describes the micromaser including collective two-atom effects, still exhibits trapping states for $ϵ\ensuremath{\ne}0$, even for a mean number of atoms inside the cavity close to one. We, however, argue more importantly that the trapping states are more pronounced in terms of the correlation length as compared to $⟨n⟩$, i.e., we suggest that trapping states can be more clearly revealed experimentally in terms of the atom correlation length. For axion detection in the micromaser this observable may, therefore, be an essential ingredient.

arXiv:quant-ph/0606233•Physical Review A•Dec 7, 2006•0 citations

Quantum phase properties of the field in a lossless micromaser cavity

Ts. Gantsog, R. Tanaś

Phase properties of the micromaser field are studied for different initial states of the cavity field and the atom. It is shown that a multipeak phase structure develops when the cavity field is initially in a coherent state and the atoms enter the cavity in their excited state, which eventually leads to the randomization of the phase. If initially the field is thermal and the atoms entering the cavity are polarized, the steady state with a considerably well defined phase is reached, which asymptotically can be one of the cotangent states or some mixed state depending on the atom-cavity interaction time. An interesting effect of switching between the two- and three-peak phase structure caused by each subsequent atom passing the cavity has been found. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Jan 1, 1996•15 citations

The micromaser possesses a variety of dynamical phase transitions parametrized by the flux of atoms and the time of flight of the atom within the cavity. We discuss how these phases may be revealed to an observer outside the cavity using the long-time correlation length in the atomic beam. Some of the phase transitions are not reflected in the average excitation level of the outgoing atom, which is the commonly used observable. The correlation length is directly related to the leading eigenvalue of the time evolution operator, which we study in order to elucidate the phase structure. We find that as a function of the time of flight the transition from the thermal to the maser phase is characterized by a sharp peak in the correlation length. For longer times of flight there is a transition to a phase where the correlation length grows exponentially with the flux. We present a detailed numerical and analytical treatment of the different phases and discuss the physics behind them. \textcopyright{} 1996 The American Physical Society.

Correlation measurements on the states of two-level atoms having passed through a micromaser at different times can be used to infer properties of the quantum state of the radiation field in the cavity. Long(short) correlation length in time is to some extent associated with super(sub)-Poissonian photon statistics. The correlation length is also an indicator of a phase structure much richer than what is revealed by the usual single-time observables, like the atomic inversion or the Mandel quality factor. In realistic experimental situations the correlations may extend over many times the decay time of the cavity. Our assertions are verified by comparing theoretical calculations with a high-precision Monte-Carlo simulation of the micromaser system.

Phase diagrams of the micromaser system are mapped out in terms of the physical parameters at hand like the atom cavity transit time, the atom-photon frequency detuning, the number of thermal photons and the probability for a pump atom to be in its excited state. Critical fluctuations are studied in terms of correlation measurements on atoms having passed through the micromaser or on the microcavity photons themselves. At sufficiently large values of the detuning we find a ``twinkling'' mode of the micromaser system. Detailed properties of the trapping states are also presented.

We study the dynamics of the single-atom maser, or micromaser, by means of the recently introduced method of thermodynamics of quantum jump trajectories. We find that the dynamics of the micromaser displays multiple space-time phase transitions, i.e., phase transitions in ensembles of quantum jump trajectories. This rich dynamical phase structure becomes apparent when trajectories are classified by dynamical observables that quantify dynamical activity, such as the number of atoms that have changed state while traversing the cavity. The space-time transitions can be either first order or continuous, and are controlled not just by standard parameters of the micromaser but also by nonequilibrium "counting" fields. We discuss how the dynamical phase behavior relates to the better known stationary-state properties of the micromaser.

In this paper we investigate the various aspects of noise and order in the micromaser system. In particular, we study the effect of adding fluctuations to the atom cavity transit time or to the atom-photon frequency detuning. By including such noise-producing mechanisms we study the probability and the joint probability for excited atoms to leave the cavity. The influence of such fluctuations on the phase structure of the micromaser as well as on the long-time atom correlation length is also discussed. We also derive the asymptotic form of micromaser observables.

We investigate signals of trapping states in the micromaser system in terms of the average number

⟨n⟩

of cavity photons as well as a suitably defined correlation length of atoms leaving the cavity. In the description of collective two-atom effects we allow the mean number,

ϵ

, of pump atoms inside the cavity during the characteristic atomic cavity transit time to be as large as of order one. The master equation we consider, which describes the micromaser including collective two-atom effects, still exhibits trapping states for $ϵ\ensuremath{\ne}0$, even for a mean number of atoms inside the cavity close to one. We, however, argue more importantly that the trapping states are more pronounced in terms of the correlation length as compared to

⟨n⟩

, i.e., we suggest that trapping states can be more clearly revealed experimentally in terms of the atom correlation length. For axion detection in the micromaser this observable may, therefore, be an essential ingredient.

Phase properties of the micromaser field are studied for different initial states of the cavity field and the atom. It is shown that a multipeak phase structure develops when the cavity field is initially in a coherent state and the atoms enter the cavity in their excited state, which eventually leads to the randomization of the phase. If initially the field is thermal and the atoms entering the cavity are polarized, the steady state with a considerably well defined phase is reached, which asymptotically can be one of the cotangent states or some mixed state depending on the atom-cavity interaction time. An interesting effect of switching between the two- and three-peak phase structure caused by each subsequent atom passing the cavity has been found. \textcopyright{} 1996 The American Physical Society.