Bloch sphere representation for Rabi oscillation driven by Rashba field in the two-dimensional harmonic confinement

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Arai, Kaichi, Tojo, Tatsuki, Takeda, Kyozaburo
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911920509943808
author Arai, Kaichi
Tojo, Tatsuki
Takeda, Kyozaburo
author_facet Arai, Kaichi
Tojo, Tatsuki
Takeda, Kyozaburo
contents We studied the dynamical properties of Rabi oscillations driven by an alternating Rashba field applied to a two-dimensional (2D) harmonic confinement system. We solve the time-dependent (TD) Schrödinger equation numerically and rewrite the resulting TD wavefunction onto the Bloch sphere (BS) using two BS parameters of the zenith ($θ_B$) and azimuthal ($ϕ_B$) angles, extracting the phase information $ϕ_B$ as well as the mixing ratio $θ_B$ between the two BS-pole states. We employed a two-state rotating wave (TSRW) approach and studied the fundamental features of $θ_B$ and $ϕ_B$ over time. The TSRW approach reveals a triangular wave formation in $θ_B$. Moreover, at each apex of the triangular wave, the TD wavefunction passes through the BS pole, and the state is completely replaced by the opposite spin state. The TSRW approach also elucidates a linear change in $ϕ_B$. The slope of $ϕ_B$ vs. time is equal to the difference between the dynamical terms, leading to a confinement potential in the harmonic system. The TSRW approach further demonstrates a jump in the phase difference by $π$ when the wavefunction passes through the BS pole. The alternating Rashba field causes multiple successive Rabi transitions in the 2D harmonic system. We then introduce the effective BS (EBS) and transform these complicated transitions into an equivalent "single" Rabi one. Consequently, the EBS parameters $θ_B^{\mathrm{eff}}$ and $ϕ_B^{\mathrm{eff}}$ exhibit mixing and phase difference between two spin states $α$ and $β$, leading to a deep understanding of the TD features of multi-Rabi oscillations. Furthermore, the combination of the BS representation with the TSRW approach successfully reveals the dynamical properties of the Rabi oscillation, even beyond the TSRW approximation.
format Preprint
id arxiv_https___arxiv_org_abs_2406_11444
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Bloch sphere representation for Rabi oscillation driven by Rashba field in the two-dimensional harmonic confinement
Arai, Kaichi
Tojo, Tatsuki
Takeda, Kyozaburo
Mesoscale and Nanoscale Physics
Materials Science
Computational Engineering, Finance, and Science
Computational Physics
Quantum Physics
We studied the dynamical properties of Rabi oscillations driven by an alternating Rashba field applied to a two-dimensional (2D) harmonic confinement system. We solve the time-dependent (TD) Schrödinger equation numerically and rewrite the resulting TD wavefunction onto the Bloch sphere (BS) using two BS parameters of the zenith ($θ_B$) and azimuthal ($ϕ_B$) angles, extracting the phase information $ϕ_B$ as well as the mixing ratio $θ_B$ between the two BS-pole states. We employed a two-state rotating wave (TSRW) approach and studied the fundamental features of $θ_B$ and $ϕ_B$ over time. The TSRW approach reveals a triangular wave formation in $θ_B$. Moreover, at each apex of the triangular wave, the TD wavefunction passes through the BS pole, and the state is completely replaced by the opposite spin state. The TSRW approach also elucidates a linear change in $ϕ_B$. The slope of $ϕ_B$ vs. time is equal to the difference between the dynamical terms, leading to a confinement potential in the harmonic system. The TSRW approach further demonstrates a jump in the phase difference by $π$ when the wavefunction passes through the BS pole. The alternating Rashba field causes multiple successive Rabi transitions in the 2D harmonic system. We then introduce the effective BS (EBS) and transform these complicated transitions into an equivalent "single" Rabi one. Consequently, the EBS parameters $θ_B^{\mathrm{eff}}$ and $ϕ_B^{\mathrm{eff}}$ exhibit mixing and phase difference between two spin states $α$ and $β$, leading to a deep understanding of the TD features of multi-Rabi oscillations. Furthermore, the combination of the BS representation with the TSRW approach successfully reveals the dynamical properties of the Rabi oscillation, even beyond the TSRW approximation.
title Bloch sphere representation for Rabi oscillation driven by Rashba field in the two-dimensional harmonic confinement
topic Mesoscale and Nanoscale Physics
Materials Science
Computational Engineering, Finance, and Science
Computational Physics
Quantum Physics
url https://arxiv.org/abs/2406.11444