Related papers: Quasi-one-dimensional quantum spin liquid in the $…
Measurements of the low-temperature thermal conductivity collected on insulators with geometrical frustration produce important experimental facts shedding light on the nature of quantum spin liquid composed of spinons. We employ a model of…
Quantum spin liquids (QSL) are novel phases of matter which remain quantum disordered even at the lowest temperature. They are characterized by emergent gauge fields and fractionalized quasiparticles. Here we show that the sub-Kelvin…
Quantum fluctuations are expected to lead to highly entangled spin-liquid states in certain two-dimensional spin-1/2 compounds. We have synthesized and measured thermodynamic properties and muon spin relaxation rates in the copper-based…
We analyze measurements of $C_{\rm mag}/T$, specific heat $C_{\rm mag}$ divided by temperature $T$, of the recently observed ultra spin liquid. The measurements are carried out in magnetic fields on the triangular lattice compound $\rm…
The main features of fermion condensation quantum phase transition (FCQPT), which are distinctive in several aspects from that of conventional quantum phase transition (CQPT), are considered. We show that in contrast to CQPT, whose physics…
Strongly correlated Fermi systems are among the most intriguing and fundamental systems in physics. We show that the herbertsmithite ZnCu3(OH)6Cl2 can be viewed as a new type of strongly correlated electrical insulator that possesses…
Experimental realization of magnetic field induced quantum phase transition (QPT) is reported for NH4CuPO4.H2O, a two spin cluster material with isotropic Heisenberg interaction. Experimental magnetization and specific heat data have been…
Exotic quantum spin liquid (QSL) is formed with such hypothetic particles as fermionic spinons carrying spin 1/2 and no charge. Here we calculate its thermodynamic and relaxation properties. Our calculations unveil the fundamental…
The low-temperature behavior of the magnetic insulator Cs2CuCl4 can be modeled by an anisotropic triangular lattice spin-1/2 Heisenberg antiferromagnet with two different exchange couplings J and J' = J/3. We show that in a wide range of…
Experimental data for the uniform susceptibility, magnetization and specific heat for the material Cu2(C5H12N2)2Cl4 (abbreviated CuHpCl) as a function of temperature and external field are compared with those of three different dimerized…
The magnetic insulator copper pyrazine dinitrate comprises antiferromagnetic spin-1/2 chains that are well described by the exactly solvable one-dimensional Heisenberg model, providing a unique opportunity for a quantitative comparison…
The long search for insulating materials that possess low-energy quasiparticles carrying electron's quantum numbers except charge - inspired by the neutral spin-1/2 excitations, the so-called spinons, exhibited by Anderson's…
The 4d-electron trimer lattice exhibits either a quantum spin liquid (QSL) or a heavy-fermion strange metal (HFSM) phase, depending on Nb content. In the QSL state, itinerant spinons act as effective heat carriers, enhancing thermal…
Quasi-particle spin susceptibility ($\chi^{qp}$) for various heavy-fermion (HF) superconductors are discussed on the basis of the experimental results of electronic specific heat ($\gamma_{el}$), NMR Knight shift ($K$) and NMR relaxation…
Thermodynamic and dynamical properties of a model of Dirac fermions with a deconfined quantum critical point (DQCP) separating an interaction-generated quantum spin-Hall insulator from an s-wave superconductor [Nature Comm.~{\bf 10}, 2658…
Conventionally ordered magnets possess bosonic elementary excitations, called magnons. By contrast, no magnetic insulators in more than one dimension are known whose excitations are not bosons but fermions. Theoretically, some quantum spin…
We analyze recent heat capacity measurements in herbertsmithite $\rm ZnCu_3(OH)_6Cl_2$ single crystal samples subjected to strong magnetic fields. We show that the temperature dependence of specific heat $C_{mag}$ formed by quantum spin…
Quantum spin liquids (QSLs) are fluid-like states of quantum spins where its long-range ordered state is destroyed by quantum fluctuations. The ground state of QSL and its exotic phenomena, which have been extensively discussed for decades,…
We describe a new kind of quantum critical point in the context of quantum anti-ferromagnetism in 2d that can be understood as a quantum critical spin liquid. Based on the comparison of exponents with previous numerical work, we argue it…
The thermodynamic behavior of the spin $S=1/2$ antiferromagnetic two-leg ladder compound $(C_{5}H_{12}N)_{2} CuBr_{4}$ in a uniform magnetic field is studied using numerical and analytical approaches. The entropy $S(H,T)$ and specific heat…