Mott transition

About: Mott transition is a research topic. Over the lifetime, 2444 publications have been published within this topic receiving 78401 citations.

Entanglement and Classical Correlations at the Doping-Driven Mott Transition in the Two-Dimensional Hubbard Model

Abstract: Tools of quantum information theory offer a new perspective to characterize phases and phase transitions in interacting many-body quantum systems. The Hubbard model is the archetypal model of such systems and can explain rich phenomena of quantum matter with minimal assumptions. Recent measurements of entanglement-related properties of this model using ultracold atoms in optical lattices hint that entanglement could provide the key to understanding open questions of the doped Hubbard model, including the remarkable properties of the pseudogap phase. These experimental findings call for a theoretical framework and new predictions. Here we approach the doped Hubbard model in two dimensions from the perspective of quantum information theory. We study the local entropy and the total mutual information across the doping-driven Mott transition within plaquette cellular dynamical mean-field theory. We find that upon varying doping these two entanglement-related properties detect the Mott insulating phase, the strongly correlated pseudogap phase, and the metallic phase. Imprinted in the entanglement-related properties we also find the pseudogap to correlated metal first-order transition, its finite temperature critical endpoint, and its supercritical crossovers. Through this footprint we reveal an unexpected interplay of quantum and classical correlations. Our work shows that sharp variation in the entanglement-related properties and not broken symmetry phases characterizes the onset of the pseudogap phase at finite temperature.

Excitonic absorption above the mott transition in Si

Abstract: We present experimental evidence for the existence of excitonic states above the excitonic Mott transition in both highly doped and highly excited silicon. Previous limitations to resolve the fundamental absorption edge of Si at dense carrier plasmas are overcome employing a novel spatially and time-resolved spectroscopy. We show that the obtained density dependent excess absorption at 75 K represents an excitonic enhancement effect, which is attributed to persisting many-body interactions.

Metal-to-Nonmetal Transition in n -Type Many-Valley Semiconductors

Abstract: We have calculated the critical donor concentration ${n}_{c}$ for the Mott transition in many-valley semiconductors. Our accurate numerical solution of the Schr\"odinger equation for Mott's model, as extended by Krieger and Nightingale, shows that previously reported good agreement with experiments has been in part the fortuitous result of calculational simplifications. We also find that the model predicts values of ${n}_{c}^{\frac{1}{3}}{a}_{H}$ (where ${a}_{H}$ is the effective Bohr radius in the material) over 45% larger in single-valley semiconductors than in Ge and Si (four and six valleys, respectively) and suggest such experiments as further meaningful tests of the model.

Thermal properties of two dimensional Mott system La1.17-xSrxVS3.17

Abstract: Experimental studies on physical properties of the two dimensional strongly correlated electron system La 1.17- x Sr x VS 3.17 have been carried out. In the x region around 0.17, where the V-valency is ∼+3, the system is considered to be in a Mott insulating phase. With increasing x up to the region \(\gtrsim0.3\), it becomes essentially metallic. Measurements of the thermal dilatation and the ultrasonic velocity have presented experimental evidence that a certain type of lattice distortion is involved in the phase transition observed previously by magnetic studies for samples with x ∼0.17. The electronic specific heat coefficient γ seems not to be enhanced as the system approaches the metal-insulator phase boundary from the metallic side.