Condensed-Matter Physics & Materials Science Seminar

In this talk I will present some parts of my recent Ph.D. work.

We have studied several aspects of unusual transport behavior near the interaction-driven metal-insulator transitions. First we examined the incoherent regime above the critical end-point temperature Tc of a single band Hubbard model at half-filling. In our analysis we found that a broad parameter range exists around the crossover line, where the family of resistivity curves displays a characteristic quantum critical scaling, which we interpreted as evidence of “hidden” Mott quantum criticality. Our results suggested that Mott quantum criticality may be acting as the fundamental mechanism behind the unusual transport phenomena in many systems near the metal-insulator transition [1].

As another example of an unconventional behavior near the interaction-driven metal-insulator transition, we have studied unusual transport associated with various inhomogeneous states emerging in the vicinity of the transition in Mn-doped electron gas. In an electronic system such inhomogeneities may result from phase separation (even in the absence of disorder) and could dramatically affect the transport. Focusing on intrinsic (electronic) phase separation, we theoretically predicted the precise experimental signatures of such a transition. We have shown that anomalous transport is expected in an intermediate regime around the transition, displaying very strong temperature and magnetic field dependence, but very weak density dependence [2].



References:
[1] H. Terletska, J. Vucicevic, D. Tanaskovic, V. Dobrosavljevic, "Quantum Critical Transport Near the Mott Transition", Phys. Rev. Lett. 107, 026401 (2011).

[2] H. Terletska and V. Dobrosavljevic, "Fingerprints of Intrinsic Phase Separation: Magnetically Doped Two-Dimensional Electron Gas", Phys. Rev. Lett. 106, 186402 (2011)