Mott transition

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

Bose–Fermi mixtures in a three-dimensional optical lattice

Abstract: Using the dynamical mean-field theory and the Gutzwiller method, we study the Mott transition in Bose–Fermi mixtures confined in a three-dimensional optical lattice and analyze the effect of fermions on the coherence of bosons. We conclude that increasing fermion composition reduces bosonic coherence in the presence of strong Bose–Fermi interactions and under the condition of the integer filling factors for composite fermions, which consist of one fermion and one or more bosonic holes. Various phases of the mixtures have been demonstrated including phase separation of two species, coexisting regions of superfluid bosons and fermionic liquids, and Mott regions in the phase space spanned by the chemical potentials of the bosons and the fermions.

Uniaxial Strain Effects on Mott and Superconducting Transitions in κ-(ET)2Cu2(CN)3

Abstract: We have investigated the anisotropic modulation of a triangular lattice in the spin-liquid Mott insulator κ-(ET) 2 Cu 2 (CN) 3 exhibiting Mott transition accompanied by superconducting transition. Under uniaxial strain along each crystal axis, the superconducting transition temperature T c plotted against the insulator–metal crossover temperature T IM increases. An increase in the superconducting upper critical field confirms the increase in T c under in-plane uniaxial strain. The result is distinct from the abrupt monotonic decrease in T c under hydrostatic pressure, indicating that electron correlation cannot be the primary origin of the enhancement of T c . We discuss uniaxial strain effects on the basis of the quadratic temperature dependence of resistivity and the results of band structure calculation.

Ultrafast Nanoscopy of High-Density Exciton Phases in WSe2.

Abstract: The density-driven transition of an exciton gas into an electron-hole plasma remains a compelling question in condensed matter physics. In two-dimensional transition metal dichalcogenides, strongly bound excitons can undergo this phase change after transient injection of electron-hole pairs. Unfortunately, unavoidable nanoscale inhomogeneity in these materials has impeded quantitative investigation into this elusive transition. Here, we demonstrate how ultrafast polarization nanoscopy can capture the Mott transition through the density-dependent recombination dynamics of electron-hole pairs within a WSe2 homobilayer. For increasing carrier density, an initial monomolecular recombination of optically dark excitons transitions continuously into a bimolecular recombination of an unbound electron-hole plasma above 7 × 1012 cm-2. We resolve how the Mott transition modulates over nanometer length scales, directly evidencing the strong inhomogeneity in stacked monolayers. Our results demonstrate how ultrafast polarization nanoscopy could unveil the interplay of strong electronic correlations and interlayer coupling within a diverse range of stacked and twisted two-dimensional materials.

Orbitally-driven Behavior: Mott Transition, Quantum Oscillations and Colossal Magnetoresistance in Bilayered Ca3Ru2O7

Abstract: We report recent transport and thermodynamic experiments over a wide range of temperatures for the Mott-like system Ca3Ru2O7 at high magnetic fields, B, up to 30 T. This work reveals a rich and highly anisotropic phase diagram, where applying B along the a-, b-, and c-axis leads to vastly different behavior. A fully spin-polarized state via a first order metamagnetic transition is obtained for B||a, and colossal magnetoresistance is seen for B||b, and quantum oscillations in the resistivity are observed for B||c, respectively. The interplay of the lattice, orbital and spin degrees of freedom are believed to give rise to this strongly anisotropic behavior.