Anomalous Cherenkov spin-orbit sound

Abstract

The Cherenkov effect is a well known phenomenon in the electrodynamics of fast charged particles passing through transparent media. If the particle is faster than the light in a given medium, the medium emits a forward light cone. This beautiful phenomenon has an acoustic counterpart where the role of photons is played by phonons and the role of the speed of light is played by the sound velocity. In this case the medium emits a forward sound cone. Here, we show that in a system with spin-orbit interactions in addition to this {\it normal} Cherenkov sound there appears an {\it anomalous} Cherenkov sound with forward and {\it backward} sound propagation. Furthermore, we demonstrate that the transition from the normal to anomalous Cherenkov sound happens in a {\it singular} way at the Cherenkov cone angle. The detection of this acoustic singularities therefore represents an alternative experimental tool for the measurement of the spin-orbit coupling strength.

published version

References in corpus (5)

• Dissipationless Quantum Spin Current at Room Temperature
• Emergence of the persistent spin helix in semiconductor quantum wells
• Measurement of Rashba and Dresselhaus spin-orbit magnetic fields
• Deduction of Pure Spin Current from Spin Linear and Circular Photogalvanic Effect in Semiconductor Quantum Wells
• Quantum dissipative Rashba spin ratchets