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:1002.1366 · Journal of the Optical Society of America B

Analyzing quantum jumps of one and two atoms strongly coupled to an optical cavity

Sebastian Reick, Klaus Mølmer, Wolfgang Alt, Martin Eckstein, Tobias Kampschulte, Lingbo Kong, René Reimann, Alexander Thobe, Artur Widera, Dieter Meschede

Published May 5, 2010• 20 citations
arXivHTMLPDF

Abstract

We induce quantum jumps between the hyperfine ground states of one and two cesium atoms, strongly coupled to the mode of a high-finesse optical resonator, and analyze the resulting random telegraph signals. We identify experimental parameters to deduce the atomic spin state nondestructively from the stream of photons transmitted through the cavity, achieving a compromise between a good signal-to-noise ratio and minimal measurement-induced perturbations. In order to extract optimum information about the spin dynamics from the photon count signal, a Bayesian update formalism is employed, which yields time-dependent probabilities for the atoms to be in one of the two hyperfine states. This analysis is extended to short time bins where a simple threshold analysis would not yield reasonable results. We discuss the effect of super-Poissonian photon number distributions caused by atomic motion.

DOI
10.1364/josab.27.00a152

Related papers

Quantum Jumps and Spin Dynamics of Interacting Atoms in a Strongly Coupled Atom-Cavity System

Mkrtych Khudaverdyan, Wolfgang Alt, Tobias Kampschulte +4 more

We experimentally investigate the spin dynamics of one and two neutral atoms strongly coupled to a high finesse optical cavity. We observe quantum jumps between hyperfine ground states of a single atom. The interaction-induced normal-mode splitting of the atom-cavity system is measured via the atomic excitation. Moreover, we observe the mutual influence of two atoms simultaneously coupled to the cavity mode.

arXiv:0901.3738•Physical Review Letters•Sep 18, 2009•52 citations

Internal and external dynamics of a strongly-coupled atom-cavity system

Sebastian Reick

A system comprised of a small number of neutral atoms coupled to the mode of a high finesse optical resonator is a model system to study light-matter interaction at the quantum level and to explore fundamental effects like the influence of the measurement process on the atomic state. Promising proposals to generate entangled states in such systems are based on the simultaneous coupling of two atoms to one resonator mode. In chapter 1 of this thesis I shortly summarise the experimental tools to capture, trap, and transport single atoms using a magneto-optical trap and an optical conveyor belt. I discuss theoretical foundations to describe our system and present numerical simulations, the results of which enter the analysis of our experimental data. The average atom-cavity coupling strength is deduced from the measured cavity transmission and compared to a model taking atomic motion into account. The dynamics of the hyperfine spin state of one and two coupled atoms is the focus of chapter 2. I describe a nondestructive cavity-based state detection method, quantify the state detection fidelity, and identify optimum experimental parameters. This method is then used to record random telegraph signals, exhibiting quantum jumps on a timescale of milliseconds. Telegraph signals for two atoms are analysed employing Bayesian statistics, yielding additional information on the evolution of the hyperfine states. A good localisation of the atom is necessary to achieve stable coupling to the cavity mode. In chapter 3, I discuss two different aspects of how the motion of the atom can be controlled. Firstly an intracavity dipole trap is characterised and it is shown that it results in improved confinement of the atom. Secondly I examine the dependence of cavity-cooling forces on our experimental parameters and compare two different cooling regimes.

•Jan 1, 2009•1 citation

Hidden Markov model of atomic quantum jump dynamics in an optically probed cavity

Søren Gammelmark, Klaus Mølmer, Wolfgang Alt +2 more

We analyze the quantum jumps of an atom interacting with a cavity field, where strong coupling makes the cavity transmission depend on the time-dependent atomic state. In our analysis we employ a Bayesian approach that conditions the population of the atomic states at time $t$ on the cavity transmission observed both before and after $t$, and we show that the state assignment by this approach is more decisive than the usual conditional quantum states based on only earlier measurement data. We also provide an iterative protocol which, together with the atomic state populations, simultaneously estimates the atomic jump rates and the transmission signal distributions from the measurement data. Finally, we take into account technical fluctuations in the observed signal, e.g., due to spatial motion of the atom within the cavity, by representing atomic states by several hidden states, thereby significantly improving the state's recovery.

arXiv:1312.5827•Physical Review A•Apr 24, 2014•36 citations

Photon statistics for two-state atoms in an optical cavity

J. J. Kimble, Robert J. Brecha, Robert J. Thompson +1 more

While for the most part quantum statistical processes in quantum optics are investigated in a weak-coupling regime, it has recently become possible to realize experimentally systems for which the internal coupling coefficient g is comparable to the external dissipative rates. Within this context the subject of our investigation is the quantum dynamical processes for a collection of N two-state atoms strongly coupled to a single mode of a high finesse optical cavity. Our particular system consists of a collection of N~20 Cesium atoms (6S 1/2, f = 4– > 6P 3/2, f = 5 transition at 852 nm) interacting with the TEMoo mode of a spherical mirror cavity of finesse 4 × 104. Of principal importance are the single atom cooperativity parameter C1 = g 2/κγ and the saturation photon number no = g2/8γ 2, where (κ,γ) are the cavity and atomic decay rates. For our system, c1~1 and n0~0.5. In measurements of the joint probability of photoelectric detection we observe photon antibunching and sub-Poissonian photon statistics.1,2 An interpretation of our results in terms of quantum state reduction and interference in a dissipative dynamical setting is presented.2 We emphasize the decisive role played by the quantum fluctuations of a single atom (c1~1), which can result in a field of large variance even in the presence of N>1 atoms.

Annual Meeting Optical Society of America•Jan 1, 1990•0 citations

Real-time measurement and trapping of single atoms by single photons

Christina J. Hood

Cavity quantum electrodynamics (QED), the system of a single atom interacting with a single mode of a high finesse optical resonator, has tremendous potential for use in quantum logic, quantum information processing, and in enabling observation of quantum mechanical effects in the laboratory. The work of this thesis demonstrates a number of steps toward realizing these goals, by employing an experimental system with the strongest atom-field coupling achieved to date in optical cavity QED. The effects of strong coupling in cavity QED are studied for single cold atoms measured one at a time, in real time. The passage of single atoms through the cavity is employed to map out the frequency response of the system, and to demonstrate that quantum rather than semiclassical theory provides the correct theoretical model. The mechanical effects of strong coupling on single atoms are explored, these experiments demonstrating the first trapping of single atoms with single photons. Additionally, strong coupling enables high signal-to-noise ratio for monitoring atomic position at single photon field strengths; this capability is employed to investigate the motion of atoms trapped within the cavity. The transmitted cavity field is used to reconstruct the trajectories of single atoms, thereby realizing a new form of microscopy - the Atom-Cavity Microscope. Technical developments necessary to create the cavities used in this experiment are detailed. Ideas for future extensions to the experiment are proposed; a zero light-shift dipole force trap, and measurement of photon statistics of a single strongly coupled atom (which realizes a photon blockade device) are discussed.

•Nov 1, 2000•16 citations

Quantum jumps of light recording the birth and death of a photon in a cavity

Stefan Kuhr, S. Gleyzes, Christine Guerlin +6 more

Summary form only given. A microscopic system under continuous observation exhibits at random times sudden jumps between its states. Quantum jumps of trapped massive particles (electrons, ions or molecules) have already been observed, which is not the case of the jumps of light quanta. Here we report on the first observation of photon number quantum jumps. Microwave photons are stored in a superconducting cavity for times in the second range. They are repeatedly probed by a stream of non-absorbing atoms. An atom interferometer measures the atomic dipole phase shift induced by the non-resonant cavity field, so that the final atom state reveals directly the presence of a single photon in the cavity. Sequences of hundreds of atoms highly correlated in the same state, are interrupted by sudden state-switchings. These telegraphic signals record, for the first time, the birth, life and death of individual photons. Applying a similar QND procedure to mesoscopic fields with tens of photons opens new perspectives for the exploration of the quantum to classical boundary.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2007•52 citations
We induce quantum jumps between the hyperfine ground states of one and two cesium atoms, strongly coupled to the mode of a high-finesse optical resonator, and analyze the resulting random telegraph signals. We identify experimental parameters to deduce the atomic spin state nondestructively from the stream of photons transmitted through the cavity, achieving a compromise between a good signal-to-noise ratio and minimal measurement-induced perturbations. In order to extract optimum information about the spin dynamics from the photon count signal, a Bayesian update formalism is employed, which yields time-dependent probabilities for the atoms to be in one of the two hyperfine states. This analysis is extended to short time bins where a simple threshold analysis would not yield reasonable results. We discuss the effect of super-Poissonian photon number distributions caused by atomic motion.
A system comprised of a small number of neutral atoms coupled to the mode of a high finesse optical resonator is a model system to study light-matter interaction at the quantum level and to explore fundamental effects like the influence of the measurement process on the atomic state. Promising proposals to generate entangled states in such systems are based on the simultaneous coupling of two atoms to one resonator mode. In chapter 1 of this thesis I shortly summarise the experimental tools to capture, trap, and transport single atoms using a magneto-optical trap and an optical conveyor belt. I discuss theoretical foundations to describe our system and present numerical simulations, the results of which enter the analysis of our experimental data. The average atom-cavity coupling strength is deduced from the measured cavity transmission and compared to a model taking atomic motion into account. The dynamics of the hyperfine spin state of one and two coupled atoms is the focus of chapter 2. I describe a nondestructive cavity-based state detection method, quantify the state detection fidelity, and identify optimum experimental parameters. This method is then used to record random telegraph signals, exhibiting quantum jumps on a timescale of milliseconds. Telegraph signals for two atoms are analysed employing Bayesian statistics, yielding additional information on the evolution of the hyperfine states. A good localisation of the atom is necessary to achieve stable coupling to the cavity mode. In chapter 3, I discuss two different aspects of how the motion of the atom can be controlled. Firstly an intracavity dipole trap is characterised and it is shown that it results in improved confinement of the atom. Secondly I examine the dependence of cavity-cooling forces on our experimental parameters and compare two different cooling regimes.
We analyze the quantum jumps of an atom interacting with a cavity field, where strong coupling makes the cavity transmission depend on the time-dependent atomic state. In our analysis we employ a Bayesian approach that conditions the population of the atomic states at time ttt on the cavity transmission observed both before and after ttt, and we show that the state assignment by this approach is more decisive than the usual conditional quantum states based on only earlier measurement data. We also provide an iterative protocol which, together with the atomic state populations, simultaneously estimates the atomic jump rates and the transmission signal distributions from the measurement data. Finally, we take into account technical fluctuations in the observed signal, e.g., due to spatial motion of the atom within the cavity, by representing atomic states by several hidden states, thereby significantly improving the state's recovery.
While for the most part quantum statistical processes in quantum optics are investigated in a weak-coupling regime, it has recently become possible to realize experimentally systems for which the internal coupling coefficient g is comparable to the external dissipative rates. Within this context the subject of our investigation is the quantum dynamical processes for a collection of N two-state atoms strongly coupled to a single mode of a high finesse optical cavity. Our particular system consists of a collection of N~20 Cesium atoms (6S 1/2, f = 4– > 6P 3/2, f = 5 transition at 852 nm) interacting with the TEMoo mode of a spherical mirror cavity of finesse 4 × 104. Of principal importance are the single atom cooperativity parameter C1 = g 2/κγ and the saturation photon number no = g2/8γ 2, where (κ,γ) are the cavity and atomic decay rates. For our system, c1~1 and n0~0.5. In measurements of the joint probability of photoelectric detection we observe photon antibunching and sub-Poissonian photon statistics.1,2 An interpretation of our results in terms of quantum state reduction and interference in a dissipative dynamical setting is presented.2 We emphasize the decisive role played by the quantum fluctuations of a single atom (c1~1), which can result in a field of large variance even in the presence of N>1 atoms.
Cavity quantum electrodynamics (QED), the system of a single atom interacting with a single mode of a high finesse optical resonator, has tremendous potential for use in quantum logic, quantum information processing, and in enabling observation of quantum mechanical effects in the laboratory. The work of this thesis demonstrates a number of steps toward realizing these goals, by employing an experimental system with the strongest atom-field coupling achieved to date in optical cavity QED. The effects of strong coupling in cavity QED are studied for single cold atoms measured one at a time, in real time. The passage of single atoms through the cavity is employed to map out the frequency response of the system, and to demonstrate that quantum rather than semiclassical theory provides the correct theoretical model. The mechanical effects of strong coupling on single atoms are explored, these experiments demonstrating the first trapping of single atoms with single photons. Additionally, strong coupling enables high signal-to-noise ratio for monitoring atomic position at single photon field strengths; this capability is employed to investigate the motion of atoms trapped within the cavity. The transmitted cavity field is used to reconstruct the trajectories of single atoms, thereby realizing a new form of microscopy - the Atom-Cavity Microscope. Technical developments necessary to create the cavities used in this experiment are detailed. Ideas for future extensions to the experiment are proposed; a zero light-shift dipole force trap, and measurement of photon statistics of a single strongly coupled atom (which realizes a photon blockade device) are discussed.
Summary form only given. A microscopic system under continuous observation exhibits at random times sudden jumps between its states. Quantum jumps of trapped massive particles (electrons, ions or molecules) have already been observed, which is not the case of the jumps of light quanta. Here we report on the first observation of photon number quantum jumps. Microwave photons are stored in a superconducting cavity for times in the second range. They are repeatedly probed by a stream of non-absorbing atoms. An atom interferometer measures the atomic dipole phase shift induced by the non-resonant cavity field, so that the final atom state reveals directly the presence of a single photon in the cavity. Sequences of hundreds of atoms highly correlated in the same state, are interrupted by sudden state-switchings. These telegraphic signals record, for the first time, the birth, life and death of individual photons. Applying a similar QND procedure to mesoscopic fields with tens of photons opens new perspectives for the exploration of the quantum to classical boundary.