Abstract
Rashba nanowires in a magnetic field exhibit a helical regime when the spin-orbit momentum is close to the Fermi momentum, . We show that this regime is characterized by a strongly anisotropic electron-spin susceptibility, with an exponentially suppressed signal along one direction in spin space, and that there are no low-frequency spin fluctuations along this direction. Since the spin response in the gapless regime has a power-law behavior in all three directions, spin measurements provide a signature of the helical regime that complements spin-insensitive conductance measurements.
- Received 3 April 2013
DOI:https://doi.org/10.1103/PhysRevB.88.035437
©2013 American Physical Society