Tuesday, July 23, 2013

1307.5427 (D. Bucheli et al.)

Phase diagrams of voltage-gated oxide interfaces with strong Rashba

D. Bucheli, M. Grilli, F. Peronaci, G. Seibold, S. Caprara
We propose a model for the two-dimensional electron gas formed at the interface of oxide heterostructures that includes a Rashba spin-orbit coupling proportional to an electric field oriented perpendicularly to the interface. Assuming that the electric field arises mainly from a non-zero electron density due to the standard mechanism of polarity catastrophe, we report the occurrence of a phase separation instability (signaled by a negative compressibility) for realistic values of the spin-orbit coupling and of the electronic band-structure parameters at zero temperature. We extend the analysis to finite temperatures and the presence of an in-plane magnetic field, thereby obtaining two phase diagrams which exhibit a phase separation dome. By varying the gating potential or the magnetic field, the phase separation dome may shrink and vanish at zero temperature into a quantum critical point where the charge fluctuates dynamically.
View original: http://arxiv.org/abs/1307.5427

No comments:

Post a Comment