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

Physical Review A

Interaction of twisted light with a trapped atom: Interplay between electronic and motional degrees of freedom

A. A. Peshkov, Y. M. Bidasyuk, R. Lange, Nils Huntemann, E. Peik, A. Surzhykov

Published Feb 13, 2023• 21 citations
Publisher

Abstract

We present a theoretical study of nondipole excitation of a single trapped atom by twisted light. Special emphasis is placed on effects that arise from the interplay between internal (electronic) and vibrational (center-of-mass) degrees of freedom of an atom. In order to provide a fully quantum mechanical understanding of the excitation, we used the density-matrix approach based on the Liouville--von Neumann equation. The developed theory has been applied to the particular case of the $4s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}3d\phantom{\rule{0.16em}{0ex}}^{2}D_{5/2}$ electric quadrupole ($E2$) transition in a $^{40}\mathrm{Ca}^{+}$ ion induced by Laguerre-Gaussian modes. It was found that the Rabi oscillations can show unconventional anharmonic behavior that is attributed to the strong coupling between vibrational levels of the trap. This effect is accompanied by the transfer of angular momentum to the center-of-mass motion and becomes most pronounced when the Rabi frequency is comparable to the trapping frequency.

DOI
10.1103/physreva.107.023106

Related papers

Optical Angular Momentum Transfer to Sub-Wavelength Quantum Systems

Andrei V. Afanasev, Maria Solyanik‐Gorgone

Twisted light, or optical vortices, can transfer angular momentum both to internal excitation of a target and to its center-of-mass (CM) motion. We use an example of electric dipole (E1) and electric quadrupole (E2) photoexcitation in a single atom to demonstrate that the internal vs CM transfer of optical angular momentum depends on atom’s location with respect to the optical vortex center and multipolarity of the quantum transition.

Frontiers in Optics•Jan 1, 2019•0 citations

Generalized excitation of atomic multipole transitions by twisted light modes

S. A.-L. Schulz, A. A. Peshkov, R. A. Müller +5 more

A theoretical study is performed for the excitation of a single atom localized in the center of twisted light modes. Here we present the explicit dependence of excitation rates on critical parameters, such as the polarization of light, its orbital angular momentum projection, and the orientation of its propagation axis with respect to the atomic quantization axis. The effect of a spatial spread of the atom is also considered in detail. The expressions for transition rates obtained in this work can be used for any atom of arbitrary electronic configuration. For definiteness we apply them to the specific case of the $^{2}S_{1/2}(F=0)\ensuremath{\rightarrow}^{2}F_{7/2}(F=3,M=0)$ electric octupole (E3) transition in ${^{171}\mathrm{Yb}}^{+}$ ion. Our analytical and numerical results are suitable for the analysis and planning of future experiments on the excitation of electric-dipole-forbidden transitions by twisted light modes in optical atomic clocks.

arXiv:2003.03360•Physical Review A•Jul 21, 2020•35 citations

Angular-momentum selection rules for photo-excitation of ions with twisted light

Andrei V. Afanasev, Maria Solyanik‐Gorgone

In this paper we analyze the novel quantum properties of atomic photo-excitations generated by Orbital Angular Momentum (OAM) photons. It was previously predicted for Bessel beams (BB), that transitionsin atomic systems driven by twisted laser beams obey a modified set of position-dependent angular-momentum selection rules. It was also shown, that in the case of perfect alignment of the atom on the beam axis, total angular momentum of the photon must be fully transferred to the internal degrees of freedom of the target, which causes dramatic enhancement of higher-multipole processes. As a result, weak atomic transitions, which are hardly observable in interactions with simple states of light, become accessible with OAM photons. In the current paper, we extend the earlier developed theory to describe atomic photoexcitations by Bessel-Gauss (BG) and Laguerre-Gauss (LG) modes. It allowed us to infer the information about the phase structure of the beam, such as mode content and topological charge. The formalism exhibits a high level of sensitivity to the polarization content of the laser beam, which is on the order of 0.005% of the polarization admixture. The theoretical predictions are confirmed experimentally for photo-excitation of Ca40+ ions, trapped in a micro-structured, segmented Paul trap. The full set of quadrupole transitions from the S-state were generated by 729nm OAM laser beam shaped with a holographic phase-plate with a fork-dislocation. The experiment was conducted by Ferdinand Schmidt-Kaler's group at the University of Mainz.

Complex Light and Optical Forces•Apr 18, 2018•2 citations

Transient optical angular momentum effects and atom trapping in multiple twisted beams

Davıd L. Andrews, A. C. Carter, M. Babiker +1 more

Theoretical work has already established the existence of a light-induced torque acting on the centre of mass of an atom, ion or molecule immersed in twisted light, where the transition frequency is suitably detuned from that of the twisted light beam. The twisted beam carries l units of orbital angular momentum per photon, and the steady-state saturation form of the torque is also determined by the width of the upper state in the atomic transition. It has been shown that, to leading order, the transfer of orbital angular momentum can only occur between the twisted light and the centre of mass motion. We argue here that, for small linewidth, the full time-dependence of the torque is needed to account correctly for the dynamics of atoms in a twisted light beam. We outline the theoretical framework needed to derive this full time-dependence, applying the theory to the motion in a twisted light beam of Eu3+ ions, which possess a particularly narrow linewidth state. For relatively large linewidth, the steady-state forces and torque are appropriate, but the processes of cooling and trapping require the application of several suitably oriented twisted beams. The description of atomic motion in multiple twisted beams demands the application of special coordinate transformations. We show how to construct the appropriate transformation matrices to represent a twisted light beam propagating in an arbitrary direction, and we proceed to investigate the cooling and trapping of Mg+ ions in sets of pairs of counter-propagating twisted beams in two-dimensional and three-dimensional molasses configurations.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 9, 2006•3 citations

Angular momentum transfer in interaction of Laguerre-Gaussian beams with atoms and molecules

Pradip Kumar Mondal, Bimalendu Deb, Sonjoy Majumder

The exchange of orbital angular momentum between a Laguerre-Gaussian beam of light and the center-of-mass motion of an atom or molecule is well known. We show that the orbital angular momentum of light can also be transferred to the internal electronic or rotational motion of an atom or a molecule provided the internal and center-of-mass motions are coupled. However, this transfer does not happen directly to the internal motion, but via center-of-mass motion. If atoms or molecules are cooled down to the recoil limit, then an exchange of angular momentum between the quantized center-of-mass motion and the internal motion is possible during the interaction of cold atoms or molecules with the Laguerre-Gaussian beam. The orientation of the exchanged angular momentum is determined by the sign of the winding number of the Laguerre-Gaussian beam. We present selective results of numerical calculations for the quadrupole transition rates in the interaction of the Laguerre-Gaussian beam with an atomic Bose-Einstein condensate to illustrate the underlying mechanism of light orbital angular momentum transfer. We discuss how the alignment of diatomic molecules will facilitate exploration of the effects of light orbital angular momentum on the electronic motion of molecules.

arXiv:1403.2881•Physical Review A•Jun 26, 2014•92 citations

Spectral Signatures of Vibronic Coupling in Trapped Cold Ionic Rydberg Systems

Joseph W. P. Wilkinson, Weibin Li, Igor Lesanovsky

Atoms and ions confined with electric and optical fields form the basis of many current quantum simulation and computing platforms. When excited to high-lying Rydberg states, long-ranged dipole interactions emerge which strongly couple the electronic and vibrational degrees of freedom through state-dependent forces. This vibronic coupling and the ensuing hybridization of internal and external degrees of freedom manifest through clear signatures in the many-body spectrum. We illustrate this by considering the case of two trapped Rydberg ions, for which the interaction between the relative vibrations and Rydberg states realizes a quantum Rabi model. We proceed to demonstrate that the aforementioned hybridization can be probed by radio frequency spectroscopy and discuss observable spectral signatures at finite temperatures and for larger ion crystals.

arXiv:2311.16998•Physical Review Letters•May 29, 2024•7 citations
We present a theoretical study of nondipole excitation of a single trapped atom by twisted light. Special emphasis is placed on effects that arise from the interplay between internal (electronic) and vibrational (center-of-mass) degrees of freedom of an atom. In order to provide a fully quantum mechanical understanding of the excitation, we used the density-matrix approach based on the Liouville--von Neumann equation. The developed theory has been applied to the particular case of the 4s2S1/2\ensuremath→3d2D5/24s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}3d\phantom{\rule{0.16em}{0ex}}^{2}D_{5/2}4s2S1/2​\ensuremath→3d2D5/2​ electric quadrupole (E2E2E2) transition in a 40Ca+^{40}\mathrm{Ca}^{+}40Ca+ ion induced by Laguerre-Gaussian modes. It was found that the Rabi oscillations can show unconventional anharmonic behavior that is attributed to the strong coupling between vibrational levels of the trap. This effect is accompanied by the transfer of angular momentum to the center-of-mass motion and becomes most pronounced when the Rabi frequency is comparable to the trapping frequency.
A theoretical study is performed for the excitation of a single atom localized in the center of twisted light modes. Here we present the explicit dependence of excitation rates on critical parameters, such as the polarization of light, its orbital angular momentum projection, and the orientation of its propagation axis with respect to the atomic quantization axis. The effect of a spatial spread of the atom is also considered in detail. The expressions for transition rates obtained in this work can be used for any atom of arbitrary electronic configuration. For definiteness we apply them to the specific case of the $^{2}S_{1/2}(F=0)\ensuremath{\rightarrow}^{2}F_{7/2}(F=3,M=0)$ electric octupole (E3) transition in 171Yb+{^{171}\mathrm{Yb}}^{+}171Yb+ ion. Our analytical and numerical results are suitable for the analysis and planning of future experiments on the excitation of electric-dipole-forbidden transitions by twisted light modes in optical atomic clocks.
In this paper we analyze the novel quantum properties of atomic photo-excitations generated by Orbital Angular Momentum (OAM) photons. It was previously predicted for Bessel beams (BB), that transitionsin atomic systems driven by twisted laser beams obey a modified set of position-dependent angular-momentum selection rules. It was also shown, that in the case of perfect alignment of the atom on the beam axis, total angular momentum of the photon must be fully transferred to the internal degrees of freedom of the target, which causes dramatic enhancement of higher-multipole processes. As a result, weak atomic transitions, which are hardly observable in interactions with simple states of light, become accessible with OAM photons. In the current paper, we extend the earlier developed theory to describe atomic photoexcitations by Bessel-Gauss (BG) and Laguerre-Gauss (LG) modes. It allowed us to infer the information about the phase structure of the beam, such as mode content and topological charge. The formalism exhibits a high level of sensitivity to the polarization content of the laser beam, which is on the order of 0.005% of the polarization admixture. The theoretical predictions are confirmed experimentally for photo-excitation of Ca40+ ions, trapped in a micro-structured, segmented Paul trap. The full set of quadrupole transitions from the S-state were generated by 729nm OAM laser beam shaped with a holographic phase-plate with a fork-dislocation. The experiment was conducted by Ferdinand Schmidt-Kaler's group at the University of Mainz.
Theoretical work has already established the existence of a light-induced torque acting on the centre of mass of an atom, ion or molecule immersed in twisted light, where the transition frequency is suitably detuned from that of the twisted light beam. The twisted beam carries l units of orbital angular momentum per photon, and the steady-state saturation form of the torque is also determined by the width of the upper state in the atomic transition. It has been shown that, to leading order, the transfer of orbital angular momentum can only occur between the twisted light and the centre of mass motion. We argue here that, for small linewidth, the full time-dependence of the torque is needed to account correctly for the dynamics of atoms in a twisted light beam. We outline the theoretical framework needed to derive this full time-dependence, applying the theory to the motion in a twisted light beam of Eu3+ ions, which possess a particularly narrow linewidth state. For relatively large linewidth, the steady-state forces and torque are appropriate, but the processes of cooling and trapping require the application of several suitably oriented twisted beams. The description of atomic motion in multiple twisted beams demands the application of special coordinate transformations. We show how to construct the appropriate transformation matrices to represent a twisted light beam propagating in an arbitrary direction, and we proceed to investigate the cooling and trapping of Mg+ ions in sets of pairs of counter-propagating twisted beams in two-dimensional and three-dimensional molasses configurations.
The exchange of orbital angular momentum between a Laguerre-Gaussian beam of light and the center-of-mass motion of an atom or molecule is well known. We show that the orbital angular momentum of light can also be transferred to the internal electronic or rotational motion of an atom or a molecule provided the internal and center-of-mass motions are coupled. However, this transfer does not happen directly to the internal motion, but via center-of-mass motion. If atoms or molecules are cooled down to the recoil limit, then an exchange of angular momentum between the quantized center-of-mass motion and the internal motion is possible during the interaction of cold atoms or molecules with the Laguerre-Gaussian beam. The orientation of the exchanged angular momentum is determined by the sign of the winding number of the Laguerre-Gaussian beam. We present selective results of numerical calculations for the quadrupole transition rates in the interaction of the Laguerre-Gaussian beam with an atomic Bose-Einstein condensate to illustrate the underlying mechanism of light orbital angular momentum transfer. We discuss how the alignment of diatomic molecules will facilitate exploration of the effects of light orbital angular momentum on the electronic motion of molecules.
Atoms and ions confined with electric and optical fields form the basis of many current quantum simulation and computing platforms. When excited to high-lying Rydberg states, long-ranged dipole interactions emerge which strongly couple the electronic and vibrational degrees of freedom through state-dependent forces. This vibronic coupling and the ensuing hybridization of internal and external degrees of freedom manifest through clear signatures in the many-body spectrum. We illustrate this by considering the case of two trapped Rydberg ions, for which the interaction between the relative vibrations and Rydberg states realizes a quantum Rabi model. We proceed to demonstrate that the aforementioned hybridization can be probed by radio frequency spectroscopy and discuss observable spectral signatures at finite temperatures and for larger ion crystals.