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

The Journal of Chemical Physics

Angular trapping and rotational dissociation of a diatomic molecule in an optical centrifuge

M. Spanner, Misha Ivanov

Published Feb 22, 2001• 30 citations
Publisher

Abstract

We perform a detailed quantum study of forced molecular rotation in an optical centrifuge, recently proposed by J. Karczmarek [Phys, Rev. Lett. 82, 3420 (1999)]. The approach uses strong nonresonant laser fields with chirped frequency to induce efficient rotational excitation of anisotropic molecules via a sequence of Raman transitions. Quantum calculations firstly of angular confinement (angular trapping) of a molecule in the early stages of the centrifuge evolution and secondly of the resulting rotational dissociation process are carried out herein. The trapping calculations include both angular degrees of freedom while the dissociation calculations include one vibrational and one rotation degree of freedom. Diatomic Cl2 is used as a test case. An extension of the scheme outlined by Karczmarek et al. is proposed as a method of producing molecules in a single selected J=Jz level.

DOI
10.1063/1.1342225

Related papers

Optical twister for molecules

J. Karzcmareck, P. B. Corkum, Misha Ivanov

Summary form only given. Optical manipulation of atoms is a well-developed and established field. Its successful use of resonant processes is difficult to mimic for molecules due to the complexity of the molecular energy spectra. However, intense non-resonant fields can provide forces similar to or even stronger than the resonant weak fields used in atom optics. These forces, long utilized in the manipulation of microscopic particles, were recently demonstrated for molecules in optical deflection and trapping experiments. We propose to use strong infrared laser field to create an "optical twister" a field that would exert very large optical torques on anisotropic molecules, leading to a controlled molecular rotation induced with a simple pulse. Molecular dissociation via rotations is used to demonstrate our method. The scheme distinguishes molecules with different moments of inertia, and thus acts as an optical centrifuge.

Conference on Lasers and Electro-Optics•Jan 20, 2003•0 citations

Rotational excitation of molecules in the regime of strong ro-vibrational coupling: Comparison between an optical centrifuge and a transform-limited pulse

J. M. García-Garrido, V. Milner, C. P. Koch +1 more

We investigate theoretically the ability of an optical centrifuge - a laser pulse whose linear polarization is rotating at an accelerated rate, to control molecular rotation in the regime when the rigid-rotor approximation breaks down due to coupling between the vibrational and rotational degrees of freedom. Our analysis demonstrates that the centrifuge field enables controlled excitation of high rotational states while maintaining relatively low spread along the vibrational coordinate. We contrast this to the rotational excitation by a linearly polarized Gaussian pulse of equal spectral width and pulse energy which, although comparable to the centrifuge-induced rotation, is unavoidably accompanied by a substantial broadening of the vibrational wavepacket.

quant-pharXiv:2512.09746•Dec 11, 2025

Nonlinear dynamics of molecular superrotors

C. Chandré, J. Pablo Salas

We consider a diatomic molecule driven by a linearly polarized laser pulse with a polarization axis rotating with a constant acceleration. This setup is referred to as optical centrifuge, and it is known to lead to high-angular momenta for the molecule (superrotor states) and, possibly, to dissociation. Here we elucidate the dynamical mechanisms behind the creation of superrotor states and their dissociation. We unravel the role of the various parameters of the laser field in these processes by considering reduced Hamiltonian models encapsulating the different phases in the creation of superrotor states, possibly leading to dissociation.

arXiv:2303.05090•Physical Review A•Jun 8, 2023•2 citations

Selective excitation of high vibrational states using Raman chirped adiabatic passage

J. C. Davis, W. S. Warren

Calculations indicate that high vibrational states of oxygen and chlorine can be excited using a series of nonresonant Raman pulses, where both the pump and the Stokes pulses are chirped with linear frequency sweeps. Most of the previously reported coherent processes (such as simple adiabatic passage) are seriously degraded when rotational effects are included. However, we find that the laser pulse parameters (intensity and bandwidth) required to invert population into high vibrational states via Raman chirped adiabatic passage are achievable using technology that is currently available. Applications to homonuclear diatomic molecules are discussed in detail.

The Journal of Chemical Physics•Mar 1, 1999•45 citations

Quantum noise in the laser-driven rotation of nonpolar molecules

Sascha Wallentowitz, Anicka Adelsward, W. Vogel

For a diatomic molecule interacting with an off-resonant laser field it is shown how quantum vacuum fluctuations of the electromagnetic field act via spontaneous Raman processes on the molecular rotational degree of freedom. Furthermore, the inclusion of the molecule's centre-of-mass and the treatment of associated photon recoil effects is outlined. The obtained results form a basis for describing the combined centre-of-mass and rotational dynamics of the molecule in off-resonant, spatially varying laser fields, such as in the laser focus forming a dipole trap.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 25, 2004•0 citations

Optical centrifuge with zero rotational acceleration

K. Wang, A. Hardikar, A. Milner +1 more

An optical centrifuge is a laser pulse which enables controlled rotational excitation of molecules. Centrifuged molecules rotating with well-defined angular frequencies are ideal candidates to probe many-body quantum systems at the nanoscale. Because the interaction with the quantum environment increases the effective moment of inertia of the embedded molecular probes, the required rotational acceleration of the optical centrifuge must be lowered to accommodate adiabatic spinning. We demonstrate a design of an optical centrifuge, based on the method of spectral focusing, which enables extremely low, down to zero, rotational accelerations. We discuss the potential of using such constant-frequency centrifuge to investigate molecular rotation inside helium nanodroplets.

Physical Review A•Oct 8, 2025•3 citations
We perform a detailed quantum study of forced molecular rotation in an optical centrifuge, recently proposed by J. Karczmarek [Phys, Rev. Lett. 82, 3420 (1999)]. The approach uses strong nonresonant laser fields with chirped frequency to induce efficient rotational excitation of anisotropic molecules via a sequence of Raman transitions. Quantum calculations firstly of angular confinement (angular trapping) of a molecule in the early stages of the centrifuge evolution and secondly of the resulting rotational dissociation process are carried out herein. The trapping calculations include both angular degrees of freedom while the dissociation calculations include one vibrational and one rotation degree of freedom. Diatomic Cl2 is used as a test case. An extension of the scheme outlined by Karczmarek et al. is proposed as a method of producing molecules in a single selected J=Jz level.
Summary form only given. Optical manipulation of atoms is a well-developed and established field. Its successful use of resonant processes is difficult to mimic for molecules due to the complexity of the molecular energy spectra. However, intense non-resonant fields can provide forces similar to or even stronger than the resonant weak fields used in atom optics. These forces, long utilized in the manipulation of microscopic particles, were recently demonstrated for molecules in optical deflection and trapping experiments. We propose to use strong infrared laser field to create an "optical twister" a field that would exert very large optical torques on anisotropic molecules, leading to a controlled molecular rotation induced with a simple pulse. Molecular dissociation via rotations is used to demonstrate our method. The scheme distinguishes molecules with different moments of inertia, and thus acts as an optical centrifuge.
We investigate theoretically the ability of an optical centrifuge - a laser pulse whose linear polarization is rotating at an accelerated rate, to control molecular rotation in the regime when the rigid-rotor approximation breaks down due to coupling between the vibrational and rotational degrees of freedom. Our analysis demonstrates that the centrifuge field enables controlled excitation of high rotational states while maintaining relatively low spread along the vibrational coordinate. We contrast this to the rotational excitation by a linearly polarized Gaussian pulse of equal spectral width and pulse energy which, although comparable to the centrifuge-induced rotation, is unavoidably accompanied by a substantial broadening of the vibrational wavepacket.
We consider a diatomic molecule driven by a linearly polarized laser pulse with a polarization axis rotating with a constant acceleration. This setup is referred to as optical centrifuge, and it is known to lead to high-angular momenta for the molecule (superrotor states) and, possibly, to dissociation. Here we elucidate the dynamical mechanisms behind the creation of superrotor states and their dissociation. We unravel the role of the various parameters of the laser field in these processes by considering reduced Hamiltonian models encapsulating the different phases in the creation of superrotor states, possibly leading to dissociation.
Calculations indicate that high vibrational states of oxygen and chlorine can be excited using a series of nonresonant Raman pulses, where both the pump and the Stokes pulses are chirped with linear frequency sweeps. Most of the previously reported coherent processes (such as simple adiabatic passage) are seriously degraded when rotational effects are included. However, we find that the laser pulse parameters (intensity and bandwidth) required to invert population into high vibrational states via Raman chirped adiabatic passage are achievable using technology that is currently available. Applications to homonuclear diatomic molecules are discussed in detail.
For a diatomic molecule interacting with an off-resonant laser field it is shown how quantum vacuum fluctuations of the electromagnetic field act via spontaneous Raman processes on the molecular rotational degree of freedom. Furthermore, the inclusion of the molecule's centre-of-mass and the treatment of associated photon recoil effects is outlined. The obtained results form a basis for describing the combined centre-of-mass and rotational dynamics of the molecule in off-resonant, spatially varying laser fields, such as in the laser focus forming a dipole trap.
An optical centrifuge is a laser pulse which enables controlled rotational excitation of molecules. Centrifuged molecules rotating with well-defined angular frequencies are ideal candidates to probe many-body quantum systems at the nanoscale. Because the interaction with the quantum environment increases the effective moment of inertia of the embedded molecular probes, the required rotational acceleration of the optical centrifuge must be lowered to accommodate adiabatic spinning. We demonstrate a design of an optical centrifuge, based on the method of spectral focusing, which enables extremely low, down to zero, rotational accelerations. We discuss the potential of using such constant-frequency centrifuge to investigate molecular rotation inside helium nanodroplets.