A Time Domain Thermo-Reflectance technique (TDTR) is used for the non-destructive evaluation of thermal and acoustic properties of Si/SiGe superlattices (SL) at room temperature. In particular, this technique allows the determination of the SL cross-plan thermal conductivity, the thermal boundary resistance at the interface between the metallic film and the SL, and the longitudinal sound veloci...

We have developed a general X-ray diffraction model which enables to investigate interfacial disorder in crystalline/amorphous and crystalline/ crystalline multilayers. Using classical structure factor calculations, we simulate the evolution of the diffracted X-ray intensities as a function of the fluctuation amplitude, the superlattice wavelength and the interatomic distances. From experimenta...

– We calculate the effects of a longitudinal electrostatic perturbation on a metallic single-wall carbon nanotube and demonstrate conductance modulation. Such external modulation would be completely screened in bulk 3D metals but is possible in SWNTs because their electrons are quasi–two-dimensional and can interact with a nearby system of charges. The resultant modulation of the conductance is...

We show that, if graphene is subjected to the potential from an external superlattice, a band gap develops at the Dirac point provided the superlattice potential has broken inversion symmetry. As numerical example, we calculate the band structure of graphene in the presence of an external potential due to periodically patterned gates arranged in a triangular graphene superlattice TGS or a squar...

The structural, magnetic, and electronic properties of (STO)4/(YTO)2 superlattice consisting of Mott insulator YTiO3 (YTO) and band insulator SrTiO3 (STO) under strain are investigated by the density-functional-theory plus U method. It is found that an insulator-metal transition occurs when a compressive strain of 0.2% is applied. The structural analyses reveal that the presence of metallic sta...

Emergent phases in the two-dimensional electron gas (2DEG) formed at the interface between two insulating oxides have attracted great attention in the past decade. We present ab-initio electronic structure calculations for the interface between a Mott insulator GdTiO3 (GTO) and a band insulator SrTiO3 (STO) and compare our results with those for the widely studied LaAlO3/SrTiO3 (LAO/STO) interf...

Strained-superlattice photocathodes based on InGaP/GaAs were investigated. The photocathode performance is found highly dependent on the superlattice parameters. The electron confinement energy in superlattice appears important.

Orbital order has been proposed theoretically for more than half a century, and has subsequently been observed in a huge range of materials. Charge ordering is generally accompanied by a transition from a metal to an insulator. In manganites, colossal magnetoresistance (CMR) is associated with competition between charge and orbital antiferromagnetic insulating phases and ferromagnetic metallic ...

Superlattice provides a new approach to enrich the class of materials with novel properties. Here, we report the structural and electronic properties of superlattices made with alternate stacking of two-dimensional hexagonal germanene (or silicene) and a MoS2 monolayer using the first principles approach. The results are compared with those of graphene/MoS2 superlattice. The distortions of the ...