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:2202.05637 · Physical Review A

Electro-optical trap for polar molecules

Břetislav Friedrich

Published May 31, 2022• 4 citations
arXivHTMLPDF

Abstract

A detailed treatment of an electro-optical trap for polar molecules, realized by embedding an optical trap within a uniform electrostatic field, is presented and the trap's properties analyzed and discussed. The electro-optical trap offers significant advantages over an optical trap that include an increased trap depth and conversion of alignment of the trapped molecules to marked orientation. Tilting the polarization plane of the optical field with respect to the electrostatic field diminishes both the trap depth and orientation and lifts the degeneracy of the $\ifmmode\pm\else\textpm\fi{}M$ states of the trapped molecules. These and other features of the electro-optical trap are examined in terms of the eigenproperties of the polar and polarizable molecules subject to the combined permanent and induced electric dipole interactions at play.

DOI
10.1103/physreva.105.053126

Related papers

Effect of rotational-state-dependent molecular alignment on the optical dipole force

Lee Yeong Kim, Ju Hyeon Lee, Hye Ah Kim +3 more

The properties of molecule-optical elements such as lenses or prisms based on the interaction of molecules with optical fields depend in a crucial way on the molecular quantum state and its alignment created by the optical field. Herein, we consider the effects of state-dependent alignment in estimating the optical dipole force acting on the molecules and, to this end, introduce an effective polarizability which takes proper account of molecular alignment and is directly related to the alignment-dependent optical dipole force. We illustrate the significance of including molecular alignment in the optical dipole force by a trajectory study that compares previously used approximations with the present approach. The trajectory simulations were carried out for an ensemble of linear molecules subject to either propagating or standing-wave optical fields for a range of temperatures and laser intensities. The results demonstrate that the alignment-dependent effective polarizability can serve to provide correct estimates of the optical dipole force, on which a state-selection method applicable to nonpolar molecules could be based. We note that an analogous analysis of the forces acting on polar molecules subject to an inhomogeneous static electric field reveals a similarly strong dependence on molecular orientation.

arXiv:1606.00516•Physical Review A•Jul 27, 2016•6 citations

Manipulation of Molecules by Combined Permanent and Induced Dipole Forces

Břetislav Friedrich

This chapter describes a versatile technique to control molecular rotation and translation. The technique is based on the combined effect of external electric fields that act concurrently on the molecular permanent and induced dipole moments. This synergistic effect arises for any polar molecule, as only an anisotropic polarizability, along with a permanent dipole moment, is required. This is always available in polar molecules. The effect of the combined fields can be achieved either by superimposing an electrostatic and a far-off resonant optical field (i.e., one that supplies electric field strength but does not cause transitions) that act, respectively, on the molecule's permanent and induced electric dipole, or by making use of a unipolar electromagnetic pulse that seizes the permanent and induced dipole moments simultaneously. If the combined electric fields are homogeneous, only molecular rotation is affected, whereas inhomogeneous fields affect both molecular rotation and translation. As noted in the chapter, the ability to manipulate molecular rotation and translation has wide-ranging applications – in research areas as diverse as reaction dynamics, spectroscopy, higher harmonic generation and molecular orbital imaging, the focusing and trapping of molecules, as well as quantum simulation and computing.

Royal Society of Chemistry eBooks•Mar 5, 2021•3 citations

Optically accessible electrostatic trap for cold polar molecules

Zhenxia Wang, Zhenxing Gu, Yong Xia +2 more

We propose an optically accessible electrostatic trap scheme to confine cold polar molecules by using two charged spherical electrodes, and we calculate the corresponding electric field distribution and the Stark trapping potential for ND3 molecules. We also propose a desirable scheme to realize an efficient loading of cold polar molecules in weak-field-seeking states, and our simulated results show that the maximal loading efficiency can reach ∼14%. In addition, we briefly discuss some potential applications of our proposed trap scheme in the studies of optical-potential evaporative cooling and electrostatic surface traps for cold polar molecules.

Journal of the Optical Society of America B•Aug 5, 2013•4 citations

Electric-field-dependent dynamic polarizability and state-insensitive conditions for optical trapping of diatomic polar molecules

Svetlana Kotochigova, David P. DeMille

Selection of state-insensitive or ``magic'' trapping conditions with ultracold atoms or molecules, where pairs of internal states experience identical trapping potentials, brings substantial benefits to precision measurements and quantum computing schemes. Working at such conditions could ensure that the detrimental effects of inevitable inhomogeneities across an ultracold sample are significantly reduced. However, this aspect of confinement remains unexplored for ultracold polar molecules. Here, we present means to control the ac Stark shift of rotational states of ultracold diatomic polar molecules, when subjected to both trapping laser light and an external electric field. We show that both the strength and relative orientation of the two fields influence the trapping potential. In particular, we predict ``magic electric field strengths'' and a ``magic angle,'' where the Stark shift is independent of the dc external field for certain rotational states of the molecule.

arXiv:1008.3856•Physical Review A•Dec 30, 2010•59 citations

Dynamic Properties of Polar Molecules Confined in Electrostatic Trap

Masatoshi Kajita, Takayuki Suzuki Takayuki Suzuki, Hitoshi Odashima +2 more

We theoretically investigate the dynamics of linear polar molecules in static quadrupole electric fields. Numerical calculation shows that molecules rotating in a specific direction experience a restoring force, being three-dimensionally trapped in the center of the field distribution. We formulate the probability of Majorana transition and the trapping lifetime with a simple model of a rotating dipole. Potential depth of the electrostatic trap is quantum-mechanically estimated to be in the order of 100 mK.

Japanese Journal of Applied Physics•Nov 1, 2001•13 citations

Towards ultracold chemistry; manipulation of polar molecules with electric fields

Jochen Küpper, Hendrick L. Bethlem, Floris M. H. Crompvoets +5 more

Deceleration and trapping of polar molecules using time-varying electric fields is described. Decelerated ND3 and OH molecules are trapped in an electrostatic trap, slow beams of ammonia are injected in a storage ring and have also been used for testing micro-structured optical elements and for high-resolution spectroscopy. Alternate gradient deceleration and AC electric trapping of ground-state molecules is discussed.

Conference on Lasers and Electro-Optics•Jan 1, 2005•0 citations
A detailed treatment of an electro-optical trap for polar molecules, realized by embedding an optical trap within a uniform electrostatic field, is presented and the trap's properties analyzed and discussed. The electro-optical trap offers significant advantages over an optical trap that include an increased trap depth and conversion of alignment of the trapped molecules to marked orientation. Tilting the polarization plane of the optical field with respect to the electrostatic field diminishes both the trap depth and orientation and lifts the degeneracy of the \ifmmode±\else\textpm\fiM\ifmmode\pm\else\textpm\fi{}M\ifmmode±\else\textpm\fiM states of the trapped molecules. These and other features of the electro-optical trap are examined in terms of the eigenproperties of the polar and polarizable molecules subject to the combined permanent and induced electric dipole interactions at play.
The properties of molecule-optical elements such as lenses or prisms based on the interaction of molecules with optical fields depend in a crucial way on the molecular quantum state and its alignment created by the optical field. Herein, we consider the effects of state-dependent alignment in estimating the optical dipole force acting on the molecules and, to this end, introduce an effective polarizability which takes proper account of molecular alignment and is directly related to the alignment-dependent optical dipole force. We illustrate the significance of including molecular alignment in the optical dipole force by a trajectory study that compares previously used approximations with the present approach. The trajectory simulations were carried out for an ensemble of linear molecules subject to either propagating or standing-wave optical fields for a range of temperatures and laser intensities. The results demonstrate that the alignment-dependent effective polarizability can serve to provide correct estimates of the optical dipole force, on which a state-selection method applicable to nonpolar molecules could be based. We note that an analogous analysis of the forces acting on polar molecules subject to an inhomogeneous static electric field reveals a similarly strong dependence on molecular orientation.
This chapter describes a versatile technique to control molecular rotation and translation. The technique is based on the combined effect of external electric fields that act concurrently on the molecular permanent and induced dipole moments. This synergistic effect arises for any polar molecule, as only an anisotropic polarizability, along with a permanent dipole moment, is required. This is always available in polar molecules. The effect of the combined fields can be achieved either by superimposing an electrostatic and a far-off resonant optical field (i.e., one that supplies electric field strength but does not cause transitions) that act, respectively, on the molecule's permanent and induced electric dipole, or by making use of a unipolar electromagnetic pulse that seizes the permanent and induced dipole moments simultaneously. If the combined electric fields are homogeneous, only molecular rotation is affected, whereas inhomogeneous fields affect both molecular rotation and translation. As noted in the chapter, the ability to manipulate molecular rotation and translation has wide-ranging applications – in research areas as diverse as reaction dynamics, spectroscopy, higher harmonic generation and molecular orbital imaging, the focusing and trapping of molecules, as well as quantum simulation and computing.
We propose an optically accessible electrostatic trap scheme to confine cold polar molecules by using two charged spherical electrodes, and we calculate the corresponding electric field distribution and the Stark trapping potential for ND3 molecules. We also propose a desirable scheme to realize an efficient loading of cold polar molecules in weak-field-seeking states, and our simulated results show that the maximal loading efficiency can reach ∼14%. In addition, we briefly discuss some potential applications of our proposed trap scheme in the studies of optical-potential evaporative cooling and electrostatic surface traps for cold polar molecules.
Selection of state-insensitive or ``magic'' trapping conditions with ultracold atoms or molecules, where pairs of internal states experience identical trapping potentials, brings substantial benefits to precision measurements and quantum computing schemes. Working at such conditions could ensure that the detrimental effects of inevitable inhomogeneities across an ultracold sample are significantly reduced. However, this aspect of confinement remains unexplored for ultracold polar molecules. Here, we present means to control the ac Stark shift of rotational states of ultracold diatomic polar molecules, when subjected to both trapping laser light and an external electric field. We show that both the strength and relative orientation of the two fields influence the trapping potential. In particular, we predict ``magic electric field strengths'' and a ``magic angle,'' where the Stark shift is independent of the dc external field for certain rotational states of the molecule.
We theoretically investigate the dynamics of linear polar molecules in static quadrupole electric fields. Numerical calculation shows that molecules rotating in a specific direction experience a restoring force, being three-dimensionally trapped in the center of the field distribution. We formulate the probability of Majorana transition and the trapping lifetime with a simple model of a rotating dipole. Potential depth of the electrostatic trap is quantum-mechanically estimated to be in the order of 100 mK.