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Maxwell Equation for the Coupled Spin-Charge Wave Propagation

B. Andrei Bernevig·Xiaowei Yu·Shou-Cheng Zhang
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Abstract

We show that the dissipationless spin current in the ground state of the Rashba model gives rise to a reactive coupling between the spin and charge propagation, which is formally identical to the coupling between the electric and the magnetic fields in the 2+1 dimensional Maxwell equation. This analogy leads to a remarkable prediction that a density packet can spontaneously split into two counter propagation packets, each carrying the opposite spins. In a certain parameter regime, the coupled spin and charge wave propagates like a transverse "photon". We propose both optical and purely electronic experiments to detect this effect.

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B. Andrei Bernevig, Xiaowei Yu, Shou-Cheng Zhang. 2004-11-10. Maxwell Equation for the Coupled Spin-Charge Wave Propagation. https://doi.org/10.1103/physrevlett.95.076602

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