TY - GEN A1 - Seibold, Götz A1 - Bucheli, Daniel A1 - Caprara, Sergio A1 - Grilli, Marco T1 - Phase separation and long-wavelength charge instabilities in spin-orbit coupled systems T2 - EPL Europhysics Letters N2 - 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. Y1 - 2015 UR - http://iopscience.iop.org/article/10.1209/0295-5075/109/17006;jsessionid=34AAE2057398BD7AE51C0C4719FC29DD.c2.iopscience.cld.iop.org U6 - https://doi.org/10.1209/0295-5075/109/17006 SN - 1286-4854 VL - 109 IS - 1 SP - 17006 ER - TY - GEN A1 - Caprara, Sergio A1 - Di Castro, Carlo A1 - Seibold, Götz A1 - Grilli, Marco T1 - Dynamical charge density waves rule the phase diagram of cuprates T2 - Physical Review B N2 - In the last few years, charge density waves (CDWs) have been ubiquitously observed in high-temperature superconducting cuprates and are now the most investigated among the competing orders in the still hot debate on these systems. A wealth of new experimental data raises several fundamental issues that challenge the various theoretical proposals. We here relate our mean-field instability line T0CDW of a strongly correlated Fermi liquid to the pseudogap T∗(p) line, marking in this way the onset of CDW-fluctuations. These fluctuations reduce strongly the mean-field critical line. Controlling this reduction via an infrared frequency cutoff related to the characteristic time of the probes, we account for the complex experimental temperature versus doping phase diagram. We provide a coherent scenario explaining why different CDW onset curves are observed by different experimental probes and seem to extrapolate at zero temperature into seemingly different quantum critical points (QCPs) in the intermediate and overdoped region. The nearly singular anisotropic scattering mediated by these fluctuations also accounts for the rapid changes of the Hall number seen in experiments and provides the first necessary step for a possible Fermi surface reconstruction fully establishing at lower doping. Finally, we show that phase fluctuations of the CDWs, which are enhanced in the presence of strong correlations near the Mott insulating phase, naturally account for the disappearance of the CDWs at low doping with yet another QCP as seen by the experiments. Y1 - 2017 UR - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.95.224511 U6 - https://doi.org/https://doi.org/10.1103/PhysRevB.95.224511 SN - 2469-9950 SN - 2469-9969 VL - 95 IS - 22 SP - 224511 ER - TY - GEN A1 - Bovenzi, Nicandro A1 - Caprara, Sergio A1 - Grilli, Marco A1 - Raimondi, Roberto A1 - Scopigno, Niccolò A1 - Seibold, Götz T1 - Density inhomogeneities and Rashba spin-orbit coupling interplay in oxide interfaces T2 - Journal of Physics and Chemistry of Solids N2 - There is steadily increasing evidence that the two-dimensional electron gas (2DEG) formed at the interface of some insulating oxides like LaAlO3/SrTiO3 and LaTiO3/SrTiO3 is strongly inhomogeneous. The inhomogeneous distribution of electron density is accompanied by an inhomogeneous distribution of the (self-consistent) electric field confining the electrons at the interface. In turn this inhomogeneous transverse electric field induces an inhomogeneous Rashba spin-orbit coupling (RSOC). After an introductory summary on two mechanisms possibly giving rise to an electronic phase separation accounting for the above inhomogeneity, we introduce a phenomenological model to describe the density-dependent RSOC and its consequences. Besides being itself a possible source of inhomogeneity or charge-density waves, the density-dependent RSOC gives rise to interesting physical effects like the occurrence of inhomogeneous spin-current distributions and inhomogeneous quantum-Hall states with chiral “edge” states taking place in the bulk of the 2DEG. The inhomogeneous RSOC can also be exploited for spintronic devices since it can be used to produce a disorder-robust spin Hall effect. Y1 - 2017 UR - https://www.sciencedirect.com/science/article/pii/S0022369717305991 SN - 0022-3697 ER - TY - JOUR A1 - Feinberg, D. A1 - Germain, P. A1 - Grilli, Marco A1 - Seibold, Götz T1 - Joint superexchange - Jahn-Teller mechanism for A-typeantiferromagnetism in LaMnO3 Y1 - 1998 ER - TY - GEN A1 - Bovenzi, Nicolo A1 - Finocchiaro, Francesca A1 - Scopigno, Nicantro A1 - Bucheli, Daniel A1 - Caprara, Sergio A1 - Seibold, Götz A1 - Grilli, Marco T1 - Possible Mechanisms of Electronic Phase Separation in Oxide Interfaces T2 - Journal of Superconductivity and Novel Magnetism N2 - LaAlO 3/SrTiO 3 and LaTiO 3/SrTiO 3 (LXO / STO) interfaces are known to host a strongly inhomogeneous (nearly) two-dimensional electron gas (2DEG). In this work, we present three unconventional electronic mechanisms of electronic phase separation (EPS) in a 2DEG as a possible source of inhomogeneity in oxide interfaces. Common to all three mechanisms is the dependence of some (interaction) potential on the 2DEGs density. We first consider a mechanism resulting from a sizable density-dependent Rashba spin-orbit coupling. Next, we point out that an EPS may also occur in the case of a density-dependent superconducting pairing interaction. Finally, we show that the confinement of the 2DEG to the interface by a density-dependent, self-consistent electrostatic potential can by itself cause an EPS. KW - Oxide interfaces KW - Superconductivity KW - Electronic phase separation Y1 - 2015 UR - http://link.springer.com/article/10.1007/s10948-014-2903-7 U6 - https://doi.org/10.1007/s10948-014-2903-7 SN - 1557-1939 SN - 1557-1947 VL - 28 IS - 4 SP - 1273 EP - 1277 ER - TY - GEN A1 - Seibold, Götz A1 - Caprara, Sergio A1 - Grilli, Marco A1 - Raimondi, Roberto T1 - On the Evaluation of the Spin Galvanic Effect in Lattice Models with Rashba Spin-Orbit Coupling T2 - Condensed matter N2 - The spin galvanic effect (SGE) describes the conversion of a non-equilibrium spin polarization into a charge current and has recently attracted renewed interest due to the large conversion efficiency observed in oxide interfaces. An important factor in the SGE theory is disorder which ensures the stationarity of the conversion. Through this paper, we propose a procedure for the evaluation of the SGE on disordered lattices which can also be readily implemented for multiband systems. We demonstrate the performance of the method for a single-band Rashba model and compare our results with those obtained within the self-consistent Born approximation for a continuum model. KW - spintronics KW - spin-galvanic effect KW - lattice models Y1 - 2018 UR - http://www.mdpi.com/2410-3896/3/3/22 U6 - https://doi.org/10.3390/condmat3030022 SN - 2410-3896 VL - 3 IS - 33 SP - 1 EP - 10 ER - TY - JOUR A1 - Seibold, Götz A1 - Grilli, Marco T1 - Influence of incommensurate dynamic charge-density wave scatteringon the line shape of superconducting high-Tc cuprates JF - Physical Review B Y1 - 2001 SN - 1550-235X VL - 63 IS - 22 SP - 224505 ER - TY - JOUR A1 - Seibold, Götz A1 - Grilli, Marco T1 - Theory of isotope dependence of photoemission spectra ofhigh-Tc superconducting cuprates Y1 - 2005 ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, A. T1 - Dynamics of Electronic Inhomogeneities in Cuprates Y1 - 2011 ER -