98%
921
2 minutes
20
We consider a trapped atomic system in the presence of spatially varying laser fields. The laser-atom interaction generates a pseudospin degree of freedom (referred to simply as spin) and leads to an effective spin-orbit coupling for the fermions in the trap. Reflections of the fermions from the trap boundaries provide a physical mechanism for effective momentum relaxation and nontrivial spin dynamics due to the emergent spin-orbit coupling. We explicitly consider evolution of an initially spin-polarized Fermi gas in a two-dimensional harmonic trap and derive nonequilibrium behavior of the spin polarization. It shows periodic echoes with a frequency equal to the harmonic trapping frequency. Perturbations, such as an asymmetry of the trap, lead to the suppression of the spin echo amplitudes. We discuss a possible experimental setup to observe spin dynamics and provide numerical estimates of relevant parameters.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.99.110403 | DOI Listing |
Phys Rev Lett
August 2025
University of Delaware, Department of Physics and Astronomy, Newark, Delaware 19716, USA.
Ultrafast light-driven strongly correlated antiferromagnetic insulators, such as prototypical NiO with a large Mott energy gap ≃4 eV, have recently attracted experimental attention using photons of both subgap [H. Qiu et al., Nat.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université, CNRS, 75005 Paris, France.
We investigate nonreciprocal XY (NRXY) models defined on two-dimensional lattices in which the coupling strength of a spin with its neighbors varies with their position in the frame defined by the current spin orientation. As expected from the seminal work of Dadhichi et al., [Nonmutual torques and the unimportance of motility for long-range order in two-dimensional flocks, Phys.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
University of York, School of Physics, Engineering and Technology, York YO10 5DD, United Kingdom.
We propose a model that is able to reproduce the type-II ultrafast demagnetization dynamics observed in 2D magnets. The spin system is coupled to the electronic thermal bath and is treated with atomistic spin dynamics, while the electron and phonon heat baths are described phenomenologically by coupled equations via the two-temperature model. Our proposed two-temperature model takes into account the effect of the heated substrate, which for 2D systems results in a slow demagnetization regime.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
Department of Chemistry, Tsinghua University, Beijing 100084, China.
A series of Cu-based single-atom catalysts (SACs) with asymmetric coordination were designed to accelerate lithium-sulfur (Li-S) chemistry. The electronegativity contrast from the dopant induces a localized electronic asymmetry that amplifies Jahn-Teller distortion at the Cu center. This distortion profoundly modulates the Cu 3d electronic structure and its interaction with Li-S intermediates.
View Article and Find Full Text PDFJ Chem Theory Comput
September 2025
Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
We present a novel, flexible framework for electronic structure interfaces designed for nonadiabatic dynamics simulations, implemented in Python 3 using concepts of object-oriented programming. This framework streamlines the development of new interfaces by providing a reusable and extendable code base. It supports the computation of energies, gradients, various couplings─like spin-orbit couplings, nonadiabatic couplings, and transition dipole moments─and other properties for an arbitrary number of states with any multiplicities and charges.
View Article and Find Full Text PDF