X. C. Hong

Quantum Transport Evidence for the Three-Dimensional Dirac Semimetal Phase in Cd 3 As 2

We report the quantum transport properties of Cd₃As₂ single crystals in a magnetic field. A large linear quantum magnetoresistance is observed near room temperature. With decreasing temperature, the Shubnikov-de Haas oscillations appear in both the longitudinal resistance R(xx) and the transverse Hall resistance R(xy). From the strong oscillatory component ΔR(xx), a linear dependence of the Landau index n on 1/B is obtained, and it gives an n-axis intercept between 1/2 and 5/8. This clearly reveals a nontrivial π Berrys phase, which is a distinguished feature of Dirac fermions. Our quantum transport results provide bulk evidence for the existence of a three-dimensional Dirac semimetal phase in Cd₃As₂.

Drastic Pressure Effect on the Extremely Large Magnetoresistance in WTe2: Quantum Oscillation Study.

The quantum oscillations of the magnetoresistance under ambient and high pressure have been studied for WTe2 single crystals, in which extremely large magnetoresistance was discovered recently. By analyzing the Shubnikov-de Haas oscillations, four Fermi surfaces are identified, and two of them are found to persist to high pressure. The sizes of these two pockets are comparable, but show increasing difference with pressure. At 0.3 K and in 14.5 T, the magnetoresistance decreases drastically from 1.25×10(5)% under ambient pressure to 7.47×10(3)% under 23.6 kbar, which is likely caused by the relative change of Fermi surfaces. These results support the scenario that the perfect balance between the electron and hole populations is the origin of the extremely large magnetoresistance in WTe2.

Absence of Magnetic Thermal Conductivity in the Quantum Spin-Liquid Candidate YbMgGaO4

We present the ultralow-temperature specific heat and thermal conductivity measurements on single crystals of YbMgGaO_{4}, which was recently argued to be a promising candidate for a quantum spin liquid (QSL). In a zero magnetic field, a large magnetic contribution of specific heat is observed, and exhibits a power-law temperature dependence (C_{m}∼T^{0.74}). On the contrary, we do not observe any significant contribution of thermal conductivity from magnetic excitations. In magnetic fields H≥6  T, the exponential T dependence of C_{m} and the enhanced thermal conductivity indicate a magnon gap of the fully polarized state. The absence of magnetic thermal conductivity at the zero field in this QSL candidate puts a strong constraint on the theories of its ground state.

Heat transport in RbFe 2 As 2 single crystals: Evidence for nodal superconducting gap

The in-plane thermal conductivity of iron-based superconductor

Experimental evidence and control of the bulk-mediated intersurface coupling in topological insulatorBi2Te2Senanoribbons

{\mathrm{RbFe}}_{2}{\mathrm{As}}_{2}

Calorimetric study of single-crystal CsFe2As2

single crystal

Nodal gap in iron-based superconductor CsFe2As2 probed by quasiparticle heat transport

({T}_{c}\ensuremath{\approx}

Nodal superconductivity in FeS: Evidence from quasiparticle heat transport

2.1 K) was measured down to 100 mK. In zero field, the observation of a significant residual linear term

Indications of topological transport by universal conductance fluctuations in Bi2Te2Se microflakes

{\ensuremath{\kappa}}_{0}/T

Anomalous impurity effects in the iron-based superconductor KFe2As2

= 0.65 mW