...
首页> 外文期刊>Physical review >Subharmonic transitions and Bloch-Siegert shift in electrically driven spin resonance
【24h】

Subharmonic transitions and Bloch-Siegert shift in electrically driven spin resonance

机译:电自旋共振中的次谐波跃迁和Bloch-Siegert位移

获取原文
获取原文并翻译 | 示例
           

摘要

We theoretically study coherent subharmonic (multiphoton) transitions of a harmonically driven spin. We consider two cases: magnetic resonance (MR) with a misaligned, i.e., nontransversal, driving field, and electrically driven spin resonance (EDSR) of an electron confined in a one-dimensional, parabolic quantum dot, subject to Rashba spin-orbit interaction. In the EDSR case, we focus on the limit where the orbital level spacing of the quantum dot is the greatest energy scale. Then, we apply time-dependent Schrieffer-Wolff perturbation theory to derive a time-dependent effective two-level Hamiltonian, allowing us to describe both MR and EDSR using the Floquet theory of periodically driven two-level systems. In particular, we characterize the fundamental (single-photon) and the half-harmonic (two-photon) spin transitions. We demonstrate the appearance of two-photon Rabi oscillations, and analytically calculate the fundamental and half-harmonic resonance frequencies and the corresponding Rabi frequencies. For EDSR, we find that both the fundamental and the half-harmonic resonance frequencies change upon increasing the strength of the driving electric field, which is an effect analogous to the Bloch-Siegert shift known from MR. Remarkably, the drive-strength-dependent correction to the fundamental EDSR resonance frequency has an anomalous, negative sign, in contrast to the corresponding Bloch-Siegert shift in MR which is always positive. Our analytical results are supported by numerical simulations, as well as by qualitative interpretations for simple limiting cases.
机译:我们从理论上研究谐波驱动自旋的相干次谐波(多光子)跃迁。我们考虑两种情况:具有未对准(即非横向)驱动场的磁共振(MR)和受一维抛物线量子点约束且受Rashba自旋轨道相互作用的电子的电驱动自旋共振(EDSR) 。在EDSR情况下,我们关注量子点的轨道能级间隔为最大能级的极限。然后,我们应用时间相关的Schrieffer-Wolff微扰理论来推导时间相关的有效两级哈密顿量,从而使我们能够使用周期驱动两级系统的Floquet理论来描述MR和EDSR。特别是,我们描述了基本(单光子)和半谐波(两光子)自旋跃迁的特征。我们演示了双光子拉比振荡的出现,并分析计算了基波和半谐波共振频率以及相应的拉比频率。对于EDSR,我们发现基本谐波谐振频率和半谐波谐振频率都会随着驱动电场强度的增加而发生变化,这类似于MR已知的Bloch-Siegert频移。值得注意的是,与驱动强度相关的基本EDSR共振频率校正具有反常的负号,这与MR中始终为正的相应的Bloch-Siegert位移相反。数值模拟以及对简单极限情况的定性解释支持了我们的分析结果。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号