Linear magnetoresistance with a universal energy scale in a strong-coupling superconductor
W. Zhang, Y. J. Hu, C. N. Kuo, S. T. Kuo, Yue-Wen Fang, Kwing To Lai, X. Y. Liu, K. Y. Yip, D. Sun, F. F. Balakirev, C. S. Lue, Hanghui Chen, Swee K. Goh
The recent discovery of a nonsaturating linear magnetoresistance in several correlated electron systems near a quantum critical point has revealed an interesting interplay between the linear magnetoresistance and the zero-field linear-in-temperature resistivity. These studies suggest a possible role of quantum criticality on the observed linear magnetoresistance. Here, we report our discovery of a nonsaturating, linear magnetoresistance in Mo$_8$Ga$_{41}$, a nearly isotropic strong electron-phonon coupling superconductor with a linear-in-temperature resistivity from the transition temperature to $\sim$55 K. The growth of the resistivity in field is comparable to that in temperature, provided that both quantities are measured in the energy unit. Our datasets are remarkably similar to magnetoresistance data of the optimally doped La$_{2-x}$Sr$_x$CuO$_4$, despite the clearly different crystal and electronic structures, and the apparent absence of quantum critical physics in Mo$_8$Ga$_{41}$. A new empirical scaling formula is developed, which is able to capture the key features of the low-temperature magnetoresistance data of Mo$_8$Ga$_{41}$, as well as the data of La$_{2-x}$Sr$_x$CuO$_4$.
Quasi-linear magnetoresistance and the violation of Kohler's rule in the quasi-one-dimensional Ta$_4$Pd$_3$Te$_{16}$ superconductor
本文报道了准一维超导体TaPDMATHABMM $_3$ Te $_{16}$（$T_c$ $\sim$ 4.6 K）正常态的准线性场内磁电阻。纵向和横向的链内磁电阻都表现出幂律依赖关系，$Δρ$ $\propto$ B $^α$，在很宽的温度和磁场范围内，指数$α$接近1。磁电阻显示没有饱和的迹象高达50特斯拉的研究。发现在Ta $_4$ Pd $_3$ Te $_{16}$中观察到的线性磁电阻与基于狄拉克费米子的量子极限、电荷电导率波动以及量子电子-电子干涉的解释总体上不一致。此外，据观察，科勒规则，无论场的方向，是违反在其正常状态。这一结果表明，这种含链化合物的正常状态下的电荷载流子的损失，可能是由于电荷密度波波动。
An analytical model invoking variations in the charge-carrier density is used to generate magnetoresistance curves that are almost indistinguishable from those produced by sophisticated numerical models. This demonstrates that, though disorder is pivotal in causing linear magnetoresistance, the form of the magnetoresistance thus generated is insensitive to details of the disorder. Taken in conjunction with the temperature ($T$) dependence of the zero-field resistivity, realistic levels of disorder are shown to be sufficient to explain the linear magnetoresistance and field-$T$ resistance scali…
Studying angle-dependent magnetoresistance oscillations of cuprate superconductors in a model with antiferromagnetic reconstruction and magnetic breakdown
The magnetoresistance of iron pnictide superconductors is often dominated by electron-electron correlations and deviates from the H$^2$ or saturating behaviors expected for uncorrelated metals. Contrary to similar Fe-based pnictide systems, the superconductor LaRu$_2$P$_2$ (T$_c$ = 4 K) shows no enhancement of electron-electron correlations. Here we report a non-saturating magnetoresistance deviating from the H$^2$ or saturating behaviors in LaRu$_2$P$_2$. We have grown and characterized high quality single crystals of LaRu$_2$P$_2$ and measured a magnetoresistance following H$^{1.3}$ up to 22…
Linear nonsaturating magnetoresistance (LMR) represents a class of anomalous resistivity response to external magnetic field that has been observed in a variety of materials including but not limited to topological semi-metals, high-Tc superconductors and materials with charge/spin density wave (CDW/SDW) orders. Here we report the observation of LMR in layered kagome superconductor and CDW material CsV3Sb5 thin flakes, as well as the dimensional crossover and temperature (T) crossover of such LMR. Specifically, in ultrathin CsV3Sb5 crystals, the magnetoresistance (MR) exhibits a crossover from…
Proposed measurements of the interlayer magnetoresistance of underdoped cuprate superconductors can distinguish closed pockets from open arcs in the Fermi surface
Ferromagnetic spin valves offer the key building blocks to integrate giant- and tunneling-magnetoresistance effects into spintronics devices. Starting from a generalized Blonder-Tinkham-Klapwijk approach, we theoretically investigate the impact of interfacial Rashba and Dresselhaus spin-orbit couplings on the tunneling conductance, and thereby the magnetoresistance characteristics, of ferromagnet/superconductor/ferromagnet spin-valve junctions embedding thin superconducting spacers between the either parallel or antiparallel magnetized ferromagnets. We focus on the unique interplay between usu…
Superconductivity and magnetism are generally incompatible because of the opposing requirement on electron spin alignment. When combined, they produce a multitude of fascinating phenomena, including unconventional superconductivity and topological superconductivity. The emergence of two-dimensional (2D)layered superconducting and magnetic materials that can form nanoscale junctions with atomically sharp interfaces presents an ideal laboratory to explore new phenomena from coexisting superconductivity and magnetic ordering. Here we report tunneling spectroscopy under an in-plane magnetic field …
Anomalous magnetoresistance in the spinel superconductor LiTi2O4
过渡金属氧化物提供了探索非常规超导体的机会，其中超导性（SC）通常与诸如自旋/电荷顺序，波动和费米表面不稳定性等新现象相关（1-3）。LiTi 2 O 4（LTO）是一种独特的化合物，因为它是唯一已知的尖晶石氧化物超导体。除了电子-声子耦合，电子-电子和自旋涨落的贡献也被认为在其超导电性的微观机制中起着重要作用（4-8）。然而，由于缺乏高质量的单晶体，迄今为止还无法对其输运性质进行系统的研究（9）。在这里，我们报告了外延LTO薄膜的输运和隧道光谱的仔细研究。在超导状态下，发现能隙作为磁场的二次函数减小。在正常状态下，观察到一个不寻常的磁阻（MR），它的变化从各向异性的积极各向同性的负，随着温度的增加。恒定的载流子浓度没有任何突然变化的晶格参数作为温度的函数表明，各向同性MR源于自旋散射/波动的抑制，而各向异性项源于轨道贡献。这些观察结果指出了强关联在这种独特的超导体中发挥的重要作用。
Sr-doped Bi2Se3 thin films was known as a potential candidate of topological superconductor. The magnetoresistance (MR) of SrxBi2Se3 films with various doping concentrations x were found to be dominated by weak antilocalization (WAL) at low magnetic fields, whereas the classical MR, which originally dominated the MR, was almost completely suppressed. In contrast, the MR of all samples has been observed to be dominated by linear magnetoresistance (LMR) at high magnetic fields. The LMR, having the linear dependence on carrier mobility, can be successfully explained by the Parish-Littlewood model…
We have investigated the in-plane anisotropy of the c-axis magnetoresistance (MR) in both superconducting and normal states of single crystals of NdO0.7F0.3BiS2 under in-plane magnetic fields. In the superconducting states of NdO0.7F0.3BiS2, four-fold-symmetric in-plane anisotropy of the c-axis MR was observed below the superconducting transition temperature. Since the crystal structure of NdO0.7F0.3BiS2 is tetragonal, the rotational symmetry in the superconducting state is preserved in the present compound. This result is clearly different from the previous report observed in LaO0.5F0.5BiSSe …
Uniaxial stress enhanced anisotropic magnetoresistance and superconductivity in the kagome superconductor LaRu$_{3}$Si$_{2}$
PSI Center for Neutron and Muon Sciences CNM（瑞士保罗谢勒研究所中子与μ子科学中心）；Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology（华中科技大学物理学院武汉国家高磁场科学中心）；Institute for Solid State Physics (ISSP), University of Tokyo（东京大学固体物理研究所）
We have measured $R(T,B)$ of a TiN thin-film very close to the disorder-driven superconductor-insulator transition but still superconducting at zero field and low temperatures. In a magnetic field we find three distinct crossing point of the magnetoresistance isotherms occur at magnetic fields $B_{cX}$ in three different temperature regions. Each crossing point in $R(T,B)$ corresponds to a plateau in $R(T,B_{cX})$. We systematically study the evolution of these crossing point near the disorder-induced superconductor/insulator transition, identify the most promising candidate for a quantum phas…
