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

Optical Control of Coherent Quantum Systems

Colin Dean Roy

Published Dec 1, 2022• 0 citations
Publisher

Abstract

Optical control of coherent quantum systems has many methods and applications. In this defense we will discuss the effects of an electric field interacting with molecules with dipole moments. The theoretical study of such molecules will consist of two-level atom and a three-level atom in the λ configuration. The methods that will be discussed are population trapping using both bright and dark starts obtained by both STIRAP and CHIRAP pulses. The application to be discussed is how to create a room temperature maser.

DOI
10.12794/metadc2048687

Related papers

Phase Control of Collective Quantum Dynamics

Mihai Macovei, Jörg Evers, Christoph H. Keitel

The manipulation of the steady-state behavior of a collection of dipole-interacting three-level atoms in a V or Lambda configuration is investigated as a function of the relative phase of two strong coherent driving fields. For larger samples, the phase is shown to be a convenient parameter to rapidly populate or depopulate completely a trapping state of the ensemble. As applications, we present the appropriately prepared atomic sample as an optical switching device and show its virtues in controlling the collective steady-state resonance fluorescence intensity.

Physical Review Letters•Dec 1, 2003•67 citations

Coherent quantum control of atomic and molecular processes by using the technique of laser pulses

龚尚庆, 钮月萍, 宋晓红 +3 more

Several schemes for coherent quantum control of atomic and molecular processes have been proposed and investigated by using the techniques of adiabatic passage and ultrashort pulses, respectively. Some interesting results have been found.

•Jan 1, 2005•0 citations

Coherent population trapping in a Λ configuration coupled by magnetic dipole interactions

Huidong Kim, Hyok Sang Han, Tai Hyun Yoon +1 more

We report our study on coherent population trapping (CPT) in a $\ensuremath{\Lambda}$ configuration coupled by magnetic dipole interactions. The $\ensuremath{\Lambda}$ configuration is formed by bichromatic radio-frequency fields coupling a pair of Zeeman sublevels in one hyperfine level of an alkali-metal atom to another sublevel in the other hyperfine level. The Zeeman sublevel at the apex is coupled to a state in the $nP$ manifold via an optical transition on one of the spectroscopic $D$ lines to induce optical pumping to a dark state. The configuration is closed without leakage to other Zeeman sublevels. We use lithium atoms in an optical trap for our experimental study. The system allows independent control of the main parameters characterizing CPT, which include the upper-state decay rate and the decoherence rate as well as the Rabi frequencies. By turning off the applied fields, the system is frozen so that its quantum state can be measured precisely. We studied the line shapes and dynamics of the CPT system, and measured the phase relation of the dark superposition state to find excellent agreement with theory. The possible application of the scheme as a method to cool optically trapped atoms below the recoil limit in a manner analogous to velocity-selective coherent population trapping is discussed.

Physical Review A•Mar 10, 2014•7 citations

Controlling Collective Quantum Dynamics with Strong Laser Fields

Mihai Macovei, Jörg Evers, Christoph H. Keitel

The control of quantum properties of driven collections of dipole interacting three-level atoms is investigated. Various parameters that allow for a rapid coherent control of collective population dynamics along with the feasibility of transferring these systems at will into subradiant or superradiant ensembles are presented.

Frontiers in Optics•Jan 1, 2004•0 citations

Quantum Coherent Control and Propagation in Lambda System

Pooja Nadkarni Singh

Strong coherence in quasi-resonant laser driven system interferes with effective relaxations, resulting in behaviors like, coherent population trapping and Electromagnetically induced transparency. The Raman system can optimize this utilizing excited coherence in the lambda system when exposed to counter- intuitive pump-stokes pulses. The phenomenon can result in complete population transfer between vibrational levels called Stimulated Raman adiabatic passage(STIRAP). STIRAP and CHIRAP have been studied with Gaussian and chirped pulses. The optical propagation effects in dense medium for these phenomenon is studied to calculate the limitations and induced coherences. Further, the effect of rotational levels has been investigated. The molecular vibrational coherence strongly depends on the effect of rotational levels. The change in coherence interaction for ro-vibrational levels are reported and explained. We have considered the effects on the phase of radiation related to rotational mechanical motion of quantum system by taking advantages in ultra strong dispersion medium provided by quantum coherence in lambda system. The enhanced Fizeau effect on a single atom is observed.

•May 1, 2016•0 citations

Weakly Aligned Molecules: From Molecular Detectors to Room-Temperature Tunable Masers

Colin Roy, Zorica Branković, Yuri V. Rostovtsev

Abstract We have developed and demonstrated a new mechanism of manipulation of population in molecular rotational levels in a weakly aligned molecules. The mechanism is based on an adiabatically changing electric field interacting with the molecules with dipole moments. Treating molecules as simple rotators, we have described their behavior using the density matrix taking into account the relaxation processes. We have considered the interaction of the weakly aligned molecules with a microwave field in a high finesse cavity. We have found that, on one hand, the population inversion can be reached in the ensemble of the weakly aligned molecules to be used for the maser operation at room temperature. On the another hand, we have found that the enhancement of the absorption can reach the theoretical limit and be used for gas sensing with high sensitivity and selectivity. Such sensors can efficiently analyze the multi-gas mixtures and be used for a huge range of applications – stretching from technology, sciences, control of environment, biology and medicine.

Journal of Physics Conference Series•Apr 1, 2022•3 citations
Optical control of coherent quantum systems has many methods and applications. In this defense we will discuss the effects of an electric field interacting with molecules with dipole moments. The theoretical study of such molecules will consist of two-level atom and a three-level atom in the λ configuration. The methods that will be discussed are population trapping using both bright and dark starts obtained by both STIRAP and CHIRAP pulses. The application to be discussed is how to create a room temperature maser.
The manipulation of the steady-state behavior of a collection of dipole-interacting three-level atoms in a V or Lambda configuration is investigated as a function of the relative phase of two strong coherent driving fields. For larger samples, the phase is shown to be a convenient parameter to rapidly populate or depopulate completely a trapping state of the ensemble. As applications, we present the appropriately prepared atomic sample as an optical switching device and show its virtues in controlling the collective steady-state resonance fluorescence intensity.
We report our study on coherent population trapping (CPT) in a $\ensuremath{\Lambda}$ configuration coupled by magnetic dipole interactions. The $\ensuremath{\Lambda}$ configuration is formed by bichromatic radio-frequency fields coupling a pair of Zeeman sublevels in one hyperfine level of an alkali-metal atom to another sublevel in the other hyperfine level. The Zeeman sublevel at the apex is coupled to a state in the nPnPnP manifold via an optical transition on one of the spectroscopic DDD lines to induce optical pumping to a dark state. The configuration is closed without leakage to other Zeeman sublevels. We use lithium atoms in an optical trap for our experimental study. The system allows independent control of the main parameters characterizing CPT, which include the upper-state decay rate and the decoherence rate as well as the Rabi frequencies. By turning off the applied fields, the system is frozen so that its quantum state can be measured precisely. We studied the line shapes and dynamics of the CPT system, and measured the phase relation of the dark superposition state to find excellent agreement with theory. The possible application of the scheme as a method to cool optically trapped atoms below the recoil limit in a manner analogous to velocity-selective coherent population trapping is discussed.
Strong coherence in quasi-resonant laser driven system interferes with effective relaxations, resulting in behaviors like, coherent population trapping and Electromagnetically induced transparency. The Raman system can optimize this utilizing excited coherence in the lambda system when exposed to counter- intuitive pump-stokes pulses. The phenomenon can result in complete population transfer between vibrational levels called Stimulated Raman adiabatic passage(STIRAP). STIRAP and CHIRAP have been studied with Gaussian and chirped pulses. The optical propagation effects in dense medium for these phenomenon is studied to calculate the limitations and induced coherences. Further, the effect of rotational levels has been investigated. The molecular vibrational coherence strongly depends on the effect of rotational levels. The change in coherence interaction for ro-vibrational levels are reported and explained. We have considered the effects on the phase of radiation related to rotational mechanical motion of quantum system by taking advantages in ultra strong dispersion medium provided by quantum coherence in lambda system. The enhanced Fizeau effect on a single atom is observed.
Abstract We have developed and demonstrated a new mechanism of manipulation of population in molecular rotational levels in a weakly aligned molecules. The mechanism is based on an adiabatically changing electric field interacting with the molecules with dipole moments. Treating molecules as simple rotators, we have described their behavior using the density matrix taking into account the relaxation processes. We have considered the interaction of the weakly aligned molecules with a microwave field in a high finesse cavity. We have found that, on one hand, the population inversion can be reached in the ensemble of the weakly aligned molecules to be used for the maser operation at room temperature. On the another hand, we have found that the enhancement of the absorption can reach the theoretical limit and be used for gas sensing with high sensitivity and selectivity. Such sensors can efficiently analyze the multi-gas mixtures and be used for a huge range of applications – stretching from technology, sciences, control of environment, biology and medicine.