A5037987179- Organic and Molecular Conductors Research
- Magnetism in coordination complexes
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Solid-state spectroscopy and crystallography
- Inorganic Chemistry and Materials
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Organometallic Compounds Synthesis and Characterization
- Perovskite Materials and Applications
- Iron-based superconductors research
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- Electronic and Structural Properties of Oxides
- Molecular Junctions and Nanostructures
- Topological Materials and Phenomena
- High-pressure geophysics and materials
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Magnetic and transport properties of perovskites and related materials
- Atomic and Subatomic Physics Research
- Ionic liquids properties and applications
The University of Tokyo
2015-2024
Max Planck Institute for Solid State Research
2023-2024
University of Stuttgart
2023-2024
Bunkyo University
2016-2019
Institute of Modern Physics
2017
Zhejiang University
2017
Collaborative Innovation Center of Advanced Microstructures
2017
RIKEN
2017
Regroupement Québécois sur les Matériaux de Pointe
2012-2014
Université de Sherbrooke
2012-2014
This article is an introductory review of the physics quantum spin liquid (QSL) states. Quantum magnetism a rapidly evolving field, and recent developments reveal that ground states low-energy frustrated systems may develop many exotic behaviors once we leave regime semi-classical approaches. The purpose this to introduce these developments. begins by explaining how approaches fail mechanics become important then describes alternative for addressing problem. We discuss mainly $1/2$ systems,...
1H NMR and static susceptibility measurements have been performed in an organic Mott insulator with a nearly isotropic triangular lattice, kappa-(BEDT-TTF)2Cu2(CN)(3), which is model system of frustrated quantum spins. The described by the spin S=1/2 antiferromagnetic triangular-lattice Heisenberg exchange constant J approximately 250 K. Regardless large magnetic interactions, spectra show no indication long-range ordering down to 32 mK, 4 orders magnitude smaller than J. These results...
Electron correlation and spin frustration are among the central issues in condensed matter physics, their interplay is expected to bring about exotic phases with both charge fluctuations. Molecular materials playgrounds suitable for this study. Fundamentals physics of Mott transition on triangular lattices seen organic ET Pd(dmit) 2 compounds. We review experimental studies criticality a continuously controllable pressure technique ground state quasi-triangular-lattice insulator. well...
Pressure-temperature phase diagram of the organic Mott insulator $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$, a model system spin liquid on triangular lattice, has been investigated by $^1$H NMR and resistivity measurements. The spin-liquid is persistent before transition to metal or superconducting under pressure. At transition, fluctuations are rapidly suppressed Fermi-liquid features observed in temperature dependence spin-lattice relaxation rate resistivity. characteristic curvature boundary...
The magnetism of an insulator, $\ensuremath{\kappa}$-(BEDT-TTF${)}_{2}$Cu[N(CN${)}_{2}$]Cl, situated near the 10 K superconducting phase in $\ensuremath{\kappa}$-type BEDT-TTF family, has been studied by ${}^{1}$H NMR for first time. A commensurate antiferromagnetic ordering with a moment (0.4--1.0) ${\ensuremath{\mu}}_{B}$/dimer was found below 26--27 K. features, quite different from conventional spin density wave, suggest that magnetic order is driven strong electron correlation rather...
One of the clear manifestations electron correlation in condensed matter is metal–insulator (MI) transition. The organic conductors κ-(ET) 2 X and (DCNQI) M are contrasting textbook materials exhibiting correlation-induced MI transition a single-π band with half filling π– d hybrid multiband tunable filling, respectively. By comparing these two systems, we learn prototypical purely electronic lattice-coupled manners.
Ternary ruthenium arsenides with the skutterudite structure, ${\mathrm{LaRu}}_{4}{\mathrm{As}}_{12}$ and ${\mathrm{PrRu}}_{4}{\mathrm{As}}_{12}$ have been prepared at high temperatures pressures. Electrical magnetic properties of both compounds studied low temperatures. Superconductivity in was found around 10.3 2.4 K, respectively. The ${T}_{c}$ is highest amongst compounds. specific heat has measured between 2 20 K. specific-heat data can be fit to expression...
Abstract The Coulomb interaction among massless Dirac fermions in graphene is unscreened around the isotropic points, causing a logarithmic velocity renormalization and cone reshaping. In less symmetric materials possessing anisotropic cones with tilted axes, can provide still more exotic phenomena, which have not been experimentally unveiled yet. Here, using site-selective nuclear magnetic resonance, we find non-uniform reshaping accompanied by bandwidth reduction an emergent ferrimagnetism...
Recent developments in research into superconductivity organic materials are reviewed. In the epoch-defining quasi-one-dimensional TMTSF superconductors with T c ∼1 K, decreases monotonically increasing pressure, as do signatures of spin fluctuations normal state, providing good evidence for magnetically-mediated pairing. Upper critical fields exceed Zeeman-limiting field by several times, suggesting triplet pairing or a transition to an inhomogeneous superconducting state at high magnetic...
Superconductivity in organic conductors is often tuned by the application of chemical or external pressure. With this type tuning, orbital overlaps and electronic bandwidths are manipulated, whilst properties molecular building blocks remain virtually unperturbed.Here, we show that excitation local vibrations charge-transfer salt $\kappa-(BEDT-TTF)_2Cu[N(CN)_2]Br$ induces a colossal increase carrier mobility opening superconducting-like optical gap. Both features track density...
A gapped spin liquid Quantum liquids avoid conventional magnetic ordering down to the lowest temperatures. Among candidates for this state of matter, organic salts such as κ-(BEDT-TTF) 2 Cu (CN) 3 have been prominent. Miksch et al. studied material using electron resonance elucidate nature its ground state. Instead expected gapless state, temperature dependence susceptibility suggests formation a gap. Science , issue p. 276
We demonstrate that an organic Mott insulator, β'-(BEDT-TTF) 2 ICl , is metallized by application of extremely high pressure means the cubic anvil press. When metallic state stabilized, superconductivity with highest transition-temperature ( T c ) among systems appears. The lower limit at which superconducting transition manifests itself approximately 7.0 GPa and reaches a maximum value, 14.2 K (onset), 8.2 GPa. pressure-temperature phase diagram constructed discussed in terms comparison...
The normal state of the layered organic superconductors $\ensuremath{\kappa}\ensuremath{-}(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\mathrm{T}\mathrm{TF}{)}_{2}X$ ( $X\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{Cu}(\mathrm{NCS}{)}_{2}$ and Cu[N(CN${)}_{2}$]Br) has been studied by ${}^{13}$C NMR for first time. nuclear spin-lattice relaxation rate, ${T}_{1}^{\ensuremath{-}1}$, is greatly enhanced over value expected from Korringa relation shows an anomalous peak...
The first nuclear magnetic resonance (NMR) evidence of charge ordering in a quasi-two-dimensional organic conductor is presented. We have performed ${}^{13}\mathrm{C}$ NMR shift and relaxation rate measurements for the conductor, $\ensuremath{\theta}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}\mathrm{RbZn}(\mathrm{SCN}{)}_{4},$ with quarter-filled band. Below metal-insulator transition at 195 K, spectrum splits into two kinds lines. spin shifts rates are quite different...
${}^{13}\mathrm{C}\ensuremath{-}\mathrm{NMR}$ measurements have been performed to investigate the nature of insulating state a quasi-one-dimensional conductor, $(\mathrm{DI}\ensuremath{-}\mathrm{DCNQI}{)}_{2}\mathrm{Ag}$, with quarter-filled band. The ${4k}_{F}$ charge-density wave has evidenced below about 220 K by line separation spectra, which shows clear charge disproportionation instead lattice dimerization encountered in most cases. present case demonstrates Wigner crystallization...
Charge distribution in the insulating phase of $\ensuremath{\theta}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}\mathrm{RbZn}(\mathrm{SCN}{)}_{4}$ [BEDT-TTF denotes bis(ethylenedithiolo)tetrathiafulvalene] is investigated using polarized Raman and infrared (IR) spectroscopy. Both IR spectra showed a multiple-peaks pattern below metal-insulator transition temperature. We assigned carbon-double-bond $(\mathrm{C}=\mathrm{C})$ stretching-modes based on isotope shift...
The static and dynamic local spin susceptibility of the organic Mott insulator $\ensuremath{\kappa}\text{\ensuremath{-}}(\mathrm{ET}{)}_{2}{\mathrm{Cu}}_{2}(\mathrm{CN}{)}_{3}$, a model material spin-1/2 triangular lattice, is studied by $^{13}\mathrm{C}$ NMR spectroscopy from room temperature down to $20\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. We observe an anomalous field-dependent spectral broadening with continuous bipolar shift distribution, appearing without critical fluctuations. It...