相关论文: Interplay of Cooper and Kondo singlet formations i…
We present high-field magnetotransport properties of high-quality single-crystalline thin films of heavily underdoped nonsuperconducting (La,Ce)2CuO4, (Pr,Ce)2CuO4, and (Nd,Ce)2CuO4. All three materials show identical behavior. They are…
Recently, the normal state resistivity of high temperature superconductors (in particular in La2-xSrxCuO4 single crystals) has been studied extensively in the region below Tc by suppressing the superconducting state in high magnetic fields.…
The transition temperature $T_\textrm{c}$ of unconventional superconductivity is often tunable. For a monolayer of FeSe, for example, the sweet spot is uniquely bound to titanium-oxide substrates. By contrast for…
We study superconducting properties in multilayer thin films consisting of superconducting La$_{1.85}$Sr$_{0.15}$CuO$_4$ (LSCO) and Mott insulator Sr$_2$IrO$_4$ (SIO) and report enhanced superconductivity in optimized sample. These…
A central issue for copper oxides is the nature of the insulating ground state at low carrier densities and the emergence of high-temperature superconductivity from that state with doping. Even though this superconductor-insulator…
We utilize terahertz time domain spectroscopy to investigate thin films of the heavy fermion compound SmB6, a prototype Kondo insulator. Temperature dependent terahertz (THz) conductivity measurements reveal a rapid decrease in the Drude…
Although it is generally accepted that superconductivity (SC) is unconventional in the high- transition temperature copper oxides (high-Tc cuprates), the relative importance of phenomena such as spin and charge (stripe) order, SC…
We report magnetoresistance and Hall Effect results for electron-doped films of the high-temperature superconductor La$_{2-x}$Ce$_x$CuO$_4$ (LCCO) for temperatures from 0.7 to 45 K and magnetic fields up to 65 T. For x = 0.12 and 0.13, just…
The transport of heat and charge in cuprates was measured in single crystals of La_{2-x}Sr_xCuO_{4+\delta} (LSCO) across the doping phase diagram at low temperatures. In underdoped LSCO, the thermal conductivity is found to decrease with…
The in-plane magnetoresistance (MR) in La2-xSrxCuO4 films with 0.03 < x < 0.05 has been studied in the temperature range 1.6 K to 100 K, and in magnetic fields up to 14 T, parallel and perpendicular to the CuO2 planes. The behavior of the…
High-temperature superconductivity has been discovered in La2-xBaxCuO4 [1], a compound that derives from the undoped La2CuO4 crystallizing in the perovskite T-structure. In this structure oxygen octahedra surround the copper ions. It is…
The evolution of the structural and transport properties of underdoped La$_{1.952}$Sr$_{0.048}$CuO$_4$ thin films under compressive epitaxial strain has been studied. The films of different thicknesses $d$ (from 26 nm to 120 nm) were…
The superconducting transition temperature, Tc, of bilayers comprising underdoped La2-xSrxCuO4 films capped by a thin heavily overdoped metallic La1.65Sr0.35CuO4 layer, is found to increase with respect to Tc of the bare underdoped films.…
A key unexplained feature of cuprate superconductors is the upturn in their normal state electrical resistivity $\rho(T)$ seen at low temperature inside the pseudogap phase. We examined this issue via measurements of the thermal…
The interplay of charge orders with superconductivity in underdoped cuprates at high magnetic fields ($H$) is an open question, and even the value of the upper critical field ($H_{c2}$), a measure of the strength of superconductivity, has…
We study two different metal-insulating transitions possibly occurring in one-dimensional Kondo lattices. First, we show how doping the pure Kondo lattice model in the strong-coupling limit, results in a Pokrovsky-Talapov transition. This…
Ultrathin amorphous Bi films, patterned with a nano-honeycomb array of holes, can exhibit an insulating phase with transport dominated by the incoherent motion of Cooper pairs of electrons between localized states. Here we show that the…
We report results of low-temperature thermodynamic and transport measurements of Pb_{1-x}Tl_{x}Te single crystals for Tl concentrations up to the solubility limit of approximately x = 1.5%. For all doped samples, we observe a…
The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we present an experimental study of single-crystal and thin film samples of La$_{2-x}$Sr$_x$CuO$_4$…
We report a novel aspect of the competition and coexistence between magnetism and superconductivity in the high-$T_{c}$ cuprate La$_{2-x}$Sr$_{x}$CuO$_{4}$ (La214). With a modest magnetic field applied $H \parallel c$-axis, we monitored the…