Dynamics of a macroscopic spin qubit in spin-orbit coupled Bose-Einstein condensates

Abstract

We consider a macroscopic spin qubit based on spin-orbit coupled Bose-Einstein condensates, where, in addition to the spin-orbit coupling, spin dynamics strongly depends on the interaction between particles. The evolution of the spin for freely expanding, trapped, and externally driven condensates is investigated. For condensates oscillating at the frequency corresponding to the Zeeman splitting in the synthetic magnetic field, the spin Rabi frequency does not depend on the interaction between the atoms since it produces only internal forces and does not change the total momentum. However, interactions and spin-orbit coupling bring the system into a mixed spin state, where the total spin is inside rather than on the Bloch sphere. This greatly extends the available spin space making it three-dimensional, but imposes limitations on the reliable spin manipulation of such a macroscopic qubit. The spin dynamics can be modified by introducing suitable spin-dependent initial phases, determined by the spin-orbit coupling, in the spinor wave function.

15 pages, 8 figures

References in corpus (9)

• Coherent control of a single electron spin with electric fields
• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Orbital mechanisms of electron spin manipulation by an electric field
• Spin-orbit coupled Bose-Einstein condensates
• Effect of Induced Spin-Orbit Coupling for Atoms via Laser Fields
• Anisotropic dynamics of a spin-orbit coupled Bose-Einstein condensate
• Spin dynamics in a strongly driven system: very slow Rabi oscillations
• Sum rules, dipole oscillation and spin polarizability of a spin-orbit coupled quantum gas
• Duality of the spin and density dynamics for two-dimensional electrons with a spin-orbit coupling