Fully Band Resolved Scattering Rate in MgB2 Revealed by Nonlinear Hall Effect and Magnetoresistance Measurements

Orbital Magnetoresistance in the LaSrCuO System

Measurements of resistivity, Hall effect, and magnetoresistance have been made on seven c-axis oriented thin-film specimens of La(2-x)Sr(x)CuO(4) with values of x from 0.048 to 0.275, and one specimen that also contains Nd. The orbital magnetoresistance is found not to be proportional to the square of the tangent of the Hall angle except for values of x near 0.15 above about 80K. For smaller values of x the temperature dependence of the magnetoresistance is different, but quite similar in the various specimens, in spite of large differences in resistivity, Hall coefficient, and Hall angle.

Magnetoresistance and Hall effect in e-doped superconducting SrLaCuO thin films

We have epitaxially grown c-axis oriented SrxLa1-xCuO2 thin films by rf sputtering on KTaO3 substrates with x = 0.12. The as-grown deposits are insulating and a series of superconducting films with various Tc(R=0) up to 26 K have been obtained by in-situ oxygen reduction. Transport measurements in the ab plane of these samples have been undertaken. We report original results on the temperature dependence of the Hall effect and on the anisotropic magnetoresistance (T > Tc). We discuss the magnitude of upper critical fields and anisotropy, the Hall effect, which presents changes of sign indicati…

Hall effect and magnetoresistance in single crystals of NdFeAsO$_{1-x}$F$_{x}$

Hall effect and magnetoresistance have been measured on single crystals of $NdFeAsO_{1-x}F_{x}$ with x = 0 ($T_c$ = 0 $ $K) and x = 0.18 ($T_c$ = 50 $ $K). For the undoped samples, strong Hall effect and magnetoresistance with strong temperature dependence were found below about 150 K. The magnetoresistance was found to be as large as 30% at 15 K at a magnetic field of 9 T. From the transport data we found that the transition near 155 K was accomplished in two steps: first one occurs at 155 K which may be associated with the structural transition, the second one takes place at about 140 K whic…

Normal-state Hall Angle and Magnetoresistance in quasi-2D Heavy Fermion CeCoIn_5 near a Quantum Critical Point

The normal-state Hall effect and magnetoresisitance (MR) have been measured in the quasi-2D heavy fermion superconductor CeCoIn_5. In the non-Fermi liquid region where the reistivity rho_xx exhibits an almost perfect T-linear dependence, the Hall angle varies as cot theta_H propto T^2 and the MR displays a strong violation of Kohler's rule. We demonstrate a novel relation between the MR and the Hall conductivity, Delta rho_xx/rho_xx propto (sigma_xy rho_xx)^2. These results bear a striking resemblance to the normal-state properties of high-T_c cuprates, indicating universal transport propertie…

Hall coefficient and magnetoresistance in boson+fermion dimer models for the pseudogap phase of high Tc superconductors

We show that the Hall coefficient of the boson+fermion dimer model for the pseudogap phase of high temperature superconductivity introduced in Punk et al. changes sign from negative at low temperatures to positive at high temperatures at a characteristic temperature scaling proportional to the the cyclotron frequency of the fermionic dimers (divided by k), (here k~0.7 fits the experimental data well). We show that this is an effect of the changing of the sign of the coupling between the fermionic dimer and the magnetic field from negative coupling -e at low temperatures to positive coupling +e…

Hall effect in the extremely large magnetoresistance semimetal WTe$_2$

We systematically measured the Hall effect in the extremely large magnetoresistance semimetal WTe$_2$. By carefully fitting the Hall resistivity to a two-band model, the temperature dependencies of the carrier density and mobility for both electron- and hole-type carriers were determined. We observed a sudden increase of the hole density below $\sim$160~K, which is likely associated with the temperature-induced Lifshitz transition reported by a previous photoemission study. In addition, a more pronounced reduction in electron density occurs below 50~K, giving rise to comparable electron and ho…

超导体 NiBi$_{3}$ 中的线性磁阻与反常霍尔效应

Linear Magnetoresistance and Anomalous Hall Effect in the Superconductor NiBi$_{3}$

本文通过磁输运测量发现超导体 NiBi$_{3}$ 单晶中存在线性磁阻与反常霍尔效应等非常规磁现象，揭示了磁涨落对电荷输运的重要作用及其磁性与拓扑交织的电子结构。

Altermagnet CrSb 中磁阻与霍尔电阻率的标度行为

Scaling Behavior of Magnetoresistance and Hall Resistivity in Altermagnet CrSb

本研究测量了Altermagnet CrSb单晶的磁阻与霍尔电阻率，发现其表现出明显的标度行为，首次在AM材料中证实磁输运性质源于本征电子结构并由洛伦兹力主导。