We investigate a two-dimensional electron model with Rashba spin-orbit interaction where the coupling constant g = g(n) depends on the electronic density. It is shown that this dependence may drive the system unstable towards a long-wavelength charge density wave (CDW) where the associated second-order instability occurs in close vicinity to global phase separation. For very low electron densities the CDW instability is nesting-induced and the modulation follows the Fermi momentum kF . At higher density the instability criterion becomes independent of kF and the system may become unstable in a broad momentum range. Finally, upon filling the upper spin-orbit split band, finite momentum instabilities disappear in favor of phase separation alone. We discuss our results with regard to the inhomogeneous phases observed at the LaAlO3/SrTiO3 or LaTiO3/SrTiO3 interfaces.
Phase separation and long wave-length charge instabilities in spin-orbit coupled systems / Seibold, GOTZ ULRICH; Bucheli, DANIEL PHILIPP; Caprara, Sergio; Grilli, Marco. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - STAMPA. - 109:(2015). [10.1209/0295-5075/109/17006]
Phase separation and long wave-length charge instabilities in spin-orbit coupled systems
SEIBOLD, GOTZ ULRICHPrimo
;BUCHELI, DANIEL PHILIPPSecondo
;CAPRARA, SERGIOPenultimo
;GRILLI, MarcoUltimo
2015
Abstract
We investigate a two-dimensional electron model with Rashba spin-orbit interaction where the coupling constant g = g(n) depends on the electronic density. It is shown that this dependence may drive the system unstable towards a long-wavelength charge density wave (CDW) where the associated second-order instability occurs in close vicinity to global phase separation. For very low electron densities the CDW instability is nesting-induced and the modulation follows the Fermi momentum kF . At higher density the instability criterion becomes independent of kF and the system may become unstable in a broad momentum range. Finally, upon filling the upper spin-orbit split band, finite momentum instabilities disappear in favor of phase separation alone. We discuss our results with regard to the inhomogeneous phases observed at the LaAlO3/SrTiO3 or LaTiO3/SrTiO3 interfaces.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.