We theoretically investigate the anisotropic dispersion features of a two-dimensional electron gas at the (110) oriented ${\mathrm{LaAlO}}_3/{\mathrm{SrTiO}}_3$ interfaces, as revealed by scanning gate microscopy of electronic flow from a quantum point contact. The dispersion relation of the (110) ${\mathrm{LaAlO}}_3/{\mathrm{SrTiO}}_3$ interface is characterized by a highly noncircular Fermi surface. Here, we develop an efficient tight-binding model for the electron gas at the interface. We show that the anisotropy of the Fermi surface causes both the direction of the electron flux from the quantum point contact and the periodicity of the self-interference conductance fringes to depend strongly on the orientation of the constriction relative to the crystal lattice. We show that the radially nonuniform distribution of the Fermi velocity on the Fermi surface results in skewing of electron trajectories when the quantum point contact gates are not aligned with the in-plane primitive vectors. We show that this effect results in the separation of electrons belonging to different orbitals for wide (110) ${\mathrm{LaAlO}}_3/{\mathrm{SrTiO}}_3$ quantum wells.

Close

PrevNext

View figure in article

• Quantum transport
• Transition metal oxides
• Two-dimensional electron gas
• S-matrix method in transport
• Scanning probe microscopy