Skyrmion-based Magnetic Traps for Ultracold Atoms

利用手性磁薄膜中的畴壁操控和捕获磁性斯格明子

Manipulation and trapping of magnetic skyrmions with domain walls in chiral magnetic thin films

本文研究利用Co/Pt超薄膜等手性磁性材料中的手性畴壁操控和捕获磁性斯格明子准粒子，通过定向斯格明子实现排斥存储、吸收形成不同拓扑结构，改变畴壁相位可擦除或存储斯格明子，为自旋电子学纳米器件提供新工具。

基于弹性位错的斯格明子陷阱：基础与应用

Elastic Dislocation-based Skyrmion Traps: Fundamentals and Applications

本文探讨畸变磁晶格中螺型位错与斯格明子的相互作用，建立拓扑磁学与拓扑弹性的联系，分析斯格明子经典及量子化运动，并举例其在低电流控制的赛道器件中的应用。

Sub-wavelength spin excitations in ultracold gases created by stimulated Raman transitions

Raman transitions are used in quantum simulations with ultracold atoms for cooling, spectroscopy and creation of artificial gauge fields. Spatial shaping of the Raman fields allows local control of the effective Rabi frequency, which can be mapped to the atomic spin. Evanescent Raman fields are of special interest as they can provide a new degree of control emanating from their rapidly decaying profile and for their ability to generate features below the diffraction limit. This opens the door to the formation of sub-wavelength spin textures. In this work, we present a theoretical and numerical…

Symmetry breaking in small rotating cloud of trapped ultracold Bose atoms

We study the signatures of rotational and phase symmetry breaking in small rotating clouds of trapped ultracold Bose atoms by looking at rigorously defined condensate wave function. Rotational symmetry breaking occurs in narrow frequency windows, where the ground state of the system has degenerated with respect to the total angular momentum, and it leads to a complex wave function that exhibits vortices clearly seen as holes in the density, as well as characteristic vorticity. Phase symmetry (or gauge symmetry) breaking, on the other hand, is clearly manifested in the interference of two indep…

Atom chips with two-dimensional electron gases: theory of near surface trapping and ultracold-atom microscopy of quantum electronic systems

We show that current in a two-dimensional electron gas (2DEG) can trap ultracold atoms $<1 μ$m away with orders of magnitude less spatial noise than a metal trapping wire. This enables the creation of hybrid systems, which integrate ultracold atoms with quantum electronic devices to give extreme sensitivity and control: for example, activating a single quantized conductance channel in the 2DEG can split a Bose-Einstein condensate (BEC) for atom interferometry. In turn, the BEC offers unique structural and functional imaging of quantum devices and transport in heterostructures and graphene.

Coherent quantum oscillations in coupled traps with ultracold atoms

The dynamics of two traps with ultracold atoms and connected by Josephson type coupling, is shown to exhibit a transition from dispersive dynamics to localized coherent oscillations. This transition is controlled by coupling strength and energy offset between the traps. The dynamics is also shown to be exactly that of a Heisenberg chain with a linear magnetic field. Possible applications for ``quantum-state engineering'' are discussed.