Related papers: Modulation of Semiconductor Superlattice Thermopow…
Energetic ion irradiation usually decreases superconducting critical temperature(Tc), with the few exceptions involving increases up to a few K only. However, our recent 2.5X10^15 Ar/cm2 irradiations by 1.5 MeV Ar6+ enhanced Tc of the…
The discovery of higher-temperature superconductivity in FeSe monolayers on SrTiO$_3$ (STO) substrates has sparked a surge of interest in the interface superconductivity. One point of the agreement reached to date is that modulation doping…
We theoretically investigate the thermoelectric properties of semiconducting (gapped) materials by varying the degrees of polynomials in their energy dispersion relations, in which either the valence or conduction energy dispersion depends…
We report on the interplay of localized and extended degrees of freedom in the metallic state of high-temperature superconductors in a multiband setting. Various ways in which the bare magnetic response may become incommensurate are…
We have studied the variation of Tc with charge density and lattice parameters in Mg1-xAlxB2 superconducting samples at low Al doping x<8%. We show that high Tc occurs where the chemical potential is tuned at a "superconducting shape…
We explore multiband effects on d-wave superconducting instabilities driven by electron-electron interactions. Our models on the two-dimensional square lattice consist of a main band with an extended Fermi surface and predominant weight…
This study systematically investigates the photoconductive properties of low-temperature-grown Beryllium (Be)-doped InGaAs/InAlAs strain-balanced superlattices (SLs) grown by molecular beam epitaxy under stationary growth conditions on…
Scanning tunneling spectroscopy (STS) studies reveal long-range spatial homogeneity and predominantly $d_{x^2-y^2}$-pairing spectral characteristics in under- and optimally doped $\rm YBa_2Cu_3O_{7-\delta}$ superconductors, whereas STS on…
We report $^{11}$B-NMR study on Al-doped MgB$_2$ that addresses a possible mechanism for a high superconducting (SC) transition temperature ($T_c$) of $\sim 40$ K in recently discovered MgB$_2$. The result of nuclear spin lattice relaxation…
Heavily doped semiconductors are by far the most studied class of materials for thermoelectric applications in the past several decades. They have Seebeck coefficient values which are 2-3 orders of magnitude higher than metals, making them…
We discuss the possibility that the strain field introduced by the structural supermodulation in Bi-2212 and certain other cuprate materials may modulate the superconducting pairing interaction. We calculate the amplitude of this effect,…
The critical temperature of an underdoped cuprate superconductor is limited by its phase stiffness $\rho$. In this Letter we argue that the dependence of $\rho$ on doping $x$ should be understood as a consequence of deleterious competition…
The doping and temperature dependence of the electronic Raman response in cuprate superconductors is studied within the framework of the kinetic energy driven superconducting mechanism for the t-J model. It is shown that the temperature…
Strain-engineering in SiGe nanostructures is fundamental for the design of optoelectronic devices at the nanoscale. Here we explore a new strategy, where SiGe structures are laterally confined by the Si substrate, to obtain high tensile…
Semiconductor nanostructures hold great promise for high-efficiency waste heat recovery exploiting thermoelectric energy conversion, a technological breakthrough that could significantly contribute to providing environmentally friendly…
The recent advent of artificial structures has triggered the emergence of fascinating phenomena that could not exist in natural compounds. A prime example is twisted multilayers, i.e., moir\'e superlattices represented by magic-angle…
We have performed density-matrix renormalization group studies of a square lattice $t$-$J$ model with small hole doping, $\delta\ll 1$, on long 4 and 6 leg cylinders. We include frustration in the form of a second-neighbor exchange…
Combining theory and certain striking phenomenology we suggest that silicene and germanene are \textit{elemental Mott insulators} and abode of doping induced high Tc superconductivity. In our theory, a 3 fold reduction in silicene $\pi -…
High-temperature copper oxide superconductors (cuprates) display unconventional physics when they are lightly doped whereas the standard theory of metals prevails in the opposite regime. For example, the thermoelectric power, that is the…
Superconductivity in flatband systems has attracted tremendous attention in condensed matter physics. Alternating twisted multilayer graphene presents a compelling multiband system, with a coexistence of Dirac bands and flat bands, for…