Mott transition

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

Effect of Fe-doping on CDW state in 1T-TaS2 investigated by STM/STS

Abstract: 1T-TaS2 has been known to undergo Mott transition from nearly commensurate charge density wave (CDW) state to commensurate CDW state at about 200 K. Recently, Fe doping was found to suppress the Mott transition and induce superconductivity. In this study, we report on the scanning tunneling microscopy (STM) and spectroscopy (STS) study on Fe doped 1T-TaS2 with different Fe concentration. STM observations reveal that the CDW superlattice becomes irregular as increasing Fe concentration. STS measurements uncover the spatial change in the local density of state (LDOS). We find two types of David-star: one has symmetric LDOS with respect to Fermi energy, and the other has asymmetric one. We identify that the asymmetric spectrum is due to an Fe dopant.

Evolution of Holographic Fermi Arcs from a Mott Insulator

Abstract: We study fermions in an electrically-probed and asymptotically anti-de Sitter Schwarzschild spacetime which interact via novel chiral symmetry-preserving interactions. Computing the dual fermion two-point correlator, we show that these bulk interactions anisotropically gap Fermi surfaces of the boundary spectrum. Consequently, the interactions we devise provide holographic models for Fermi arcs seen ubiquitously in the pseudogap regime of the cuprates. Our interactions are modifications of the chiral symmetry-breaking Pauli coupling, which has previously been proposed as the holographic realization of Mott physics. The onset of Mott insulation and pseudogap physics are respectively discussed in the context of bulk chiral and boundary parity symmetry breaking, and the Mott transition is interpreted as a deconfinement transition of non-Fermi liquid excitations.

The Role of the Short Coherence Length in Unconventional Superconductors

Abstract: A short coherence length is a distinctive feature of many cases of unconventional superconductivity. While in conventional superconductors, it is many orders of magnitude larger than the basic inter-particle distance, a short coherence length is common to superconductors as diverse as the cuprates, the picnites and granular superconductors. We dwell particularly on the last, because their simple chemical structure makes them a favorable material for exploring fundamental phenomena such as the Bardeen-Cooper Schrieffer (BCS)-to-Bose–Einstein condensation cross-over and the effect of the vicinity of a Mott metal-to-insulator transition.

Manufacture of field effect transistor having buried mott material oxide channel

Abstract: PROBLEM TO BE SOLVED: To obtain a structure and a manufacturing method of a FET having a buried Mott insulating oxide channel. SOLUTION: A structure and a forming method of a field effect transistor having a buried Mott insulating oxide channel comprises the steps of depositing a source electrode and a drain electrode on a substrate 101, forming a Mott transition channel layer 201 on the substrate 101 and the electrodes, forming an insulator layer on the Mott transition channel layer 201, forming a source contact and a drain contact via the insulator layer (so that the source contact and the drain contact are electrically connected to the Mott transition channel layer), and forming a gate electrode 402 on the insulator layer between the source contact and the drain contact.

Exciton Mott transition and quantum condensation in electron-hole systems

Abstract: This paper reviews recent progress of theoretical studies on the metal-insulator transition and the quantum condensation in photoexcited states, the electron-hole (eh) systems, which are modeled by the e-h (two-band) Hubbard model with both repulsive U and attractive U ′ on-site interactions. We confine ourselves to a quasithermal-equilibrium situation. First, we introduce the dynamical mean-field theory (DMFT) applied to the metalinsulator transition (called the “exciton Mott transition”) of the high-dimensional e-h systems at zero and finite temperatures T.We determined the phase diagram of the e-h Hubbard model and the first-order exciton Mott transition line in the plane of the (U ′;U) or (U = U ′ T). We find two types of insulating phases: exciton-like and biexciton-like. At the Mott critical temperature such first-order Mott transition disappears, and the crossover is observed above the critical temperature. Comparison with results by the slave-boson mean-field treatment is also made. Role of the inter-site interaction is also discussed with the use of the extended DMFT. Second, we discuss the crossover between the exciton Bose-Einstein condensation and the e-h BCStype condensed state at low temperature using the selfconsistent t -matrix and local approximations within the framework of DMFT. We evaluate the transition temperature as a function of the interaction strength. Effects of repulsive on-site interaction are analyzed. Third, for a one-dimensional e-h system, the bosonization and renormalization-group techniques clarify that the most probable ground state is the insulating biexciton crystal, reflecting the e-h backward scattering and the long-range Coulomb interaction. The exciton Mott transition never occurs at zero temperature in one dimension. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)