Related papers: Is a doped 'Kondo' insulator different from doped …
In the ballistic regime, the metallic temperature dependence of the conductivity in a two-dimensional electron system in silicon is found to change non-monotonically with the degree of spin polarization. In particular, it fades away just…
We investigate the influence of an unoccupied band on the transport properties of a strongly correlated electron system. For that purpose, additional orbitals are coupled to a Hubbard model via hybridization. The filling is one electron per…
The amorphous conducting carbon films have been prepared at three different preparation temperatures with different boron-doping levels. The structural and transport properties of the same have been studied. X-ray diffraction measurements…
In the present work, an infrared LED is used to photodope MBE-grown Si:Al(0.3)Ga(0.7)As, a well known persistent photoconductor, to vary the effective electron concentration of samples in situ. Using this technique, we examine the transport…
Kondo insulators are predicted to undergo an insulator-to-metal transition under applied magnetic field, yet the extremely high fields required to date have prohibited a comprehensive investigation of the nature of this transition. Here we…
Results of DC and frequency dependent conductivity in the quantum limit, i.e. hw > kT, for a broad range of dopant concentrations in nominally uncompensated, crystalline phosphorous doped silicon and amorphous niobium-silicon alloys are…
We present a comprehensive investigation of the structural, electrical transport, and magnetic properties of FeSe$_{\it{x}}$ ($\it{x}$ = 1.14, 1.18, 1.23, 1.28, and 1.32) to unravel the mechanism of the metal-insulator transition observed…
Measurements of conductance $G$ on short, wide, high-mobility Si-MOSFETs reveal both a two-dimensional metal-insulator transition (MIT) at moderate temperatures (1 $<~ T <$ 4~K) and mesoscopic fluctuations of the conductance at low…
Kondo insulator FeSb$_2$ with large Seebeck coefficient would have potential in thermoelectric applications in cryogenic temperature range if it had not been for large thermal conductivity $\kappa$. Here we studied the influence of…
The influence of a rotating magnetic field (in the $ab-$plane) on the density of states has been investigated in the superconducting state of the nematic FeSe superconductor using high sensitivity specific heat measurements. As expected for…
We have measured the conductivity of high-mobility (001) Si metal-oxide-semiconductor field effect transistors (MOSFETs) over wide ranges of electron densities n=(1.8-15)x10^11cm^2, temperatures T=30mK-4.2K, and in-plane magnetic fields…
The temperature dependence of conductivity $\sigma (T)$ of a two-dimensional electron system in silicon has been studied in parallel magnetic fields B. At B=0, the system displays a metal-insulator transition at a critical electron density…
We consider the two-terminal conductance of a one-dimensional Mott insulator undergoing the commensurate-incommensurate quantum phase transition to a conducting state. We treat the leads as Luttinger liquids. At a specific value of…
We present a detailed investigation of the magnetic and structural properties of magnetically doped 3D topological insulator Bi2Se3. From muon spin relaxation measurements in zero magnetic field, we find that even 5% Fe doping on the Bi…
We report the observation of TEMPERATURE-INDUCED transitions between insulator, metal, and quantum-Hall behaviors for transport coefficients in the very dilute high mobility two-dimensional electron system in silicon. We consider the…
In the electron doped compounds SrFe_(2-x)Co_xAs_2 superconductivity with T_c up to 20 K is observed for 0.2 < x < 0.4. Results of structure determination, magnetic susceptibility, electrical resistivity, and specific heat are reported. The…
Transport and magnetic properties have been systematically investigated for SmMnAsO_{1-x} with controlled electron-doping. As the electron band-filling is increased with the increase of oxygen deficiency (x), the resistivity monotonically…
Hyperdoping has emerged as a promising method for designing semiconductors with unique optical and electronic properties, although such properties currently lack a clear microscopic explanation. Combining computational and experimental…
Measurements of the DC resistivity of under-doped cuprate superconductors have revealed a metal--insulator transition at low temperatures when superconductivity is suppressed by a very large magnetic field, with the resistivity growing…
To investigate whether the dense Kondo compound CeB6 might evolve into a topological insulator under sufficient pressure, four-point electrical resistivity measurements have been carried out over the temperature range 1.3 K to 295 K in a…