相关论文: Intersubband carrier scattering in n- and p-Si/SiG…

Electron spin qubits in Si/SiGe quantum wells are limited by the small and variable energy separation of the conduction band valleys. While sharp quantum well interfaces are pursued to increase the valley splitting energy deterministically,…

We investigate the disorder properties of two-dimensional hole gases in Ge/SiGe heterostructures grown on Ge wafers, using thick SiGe barriers to mitigate the influence of the semiconductor-dielectric interface. Across several…

Scattering processes by the interface roughness in a quantum well in a quantizing magnetic field are considered. An expression for the scattering rate is derived for a magnetic field tilted relative to the quantum well layers. By analyzing…

Intervalley mixing between conduction-band states in low-dimensional Si/SiGe heterostructures induces splitting between nominally degenerate energy levels. The symmetric double-valley effective mass approximation and the empirical…

A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface…

Motivated by theoretical predictions that spatially complex concentration modulations of Si and Ge can increase the valley splitting in quantum wells, we grow and characterize Si/SiGe heterostructures with a thin, pure Ge layer at the top…

Electron spins in Si/SiGe quantum wells suffer from nearly degenerate conduction band valleys, which compete with the spin degree of freedom in the formation of qubits. Despite attempts to enhance the valley energy splitting…

We develop a generalized theory for the scattering process produced by interface roughness on charge carriers and which is suitable for any semiconductor heterostructure. By exploiting our experimental insights into the three-dimensional…

We calculate the intersubband absorption linewidth in quantum wells (QWs) due to scattering by interface roughness, LO phonons, LA phonons, alloy disorder, and ionized impurities, and compare it with the transport energy broadening that…

In IV-VI semiconductor heterojunctions with band-inversion, such as those made of Pb$_{1-x}$Sn$_{x}$Te or Pb$_{1-x}$Sn$_{x}$Se, interface states are properly described by a two-band model, predicting the appearance of a Dirac cone in single…

We study molecular beam epitaxially grown, undoped Al$_{x}$Ga$_{1-x}$Sb/InAs/AlSb quantum wells with different buffer and barrier designs and varying quantum well width. The highest mobilities were achieved with Al$_{0.33}$Ga$_{0.67}$Sb…

We used Raman scattering for study the phonon modes of self-organized Ge/Si quantum dots, grown by a molecular-beam epitaxy method. It is revealed, that Ge-Ge and Si-Ge vibrational modes considerably intensify at excitation of exciton…

We report low-temperature magneto-transport measurements of an undoped Si/SiGe asymmetric double quantum well heterostructure. The density in both layers is tuned independently utilizing a top and a bottom gate, allowing the investigation…

We present molecular beam epitaxial grown single- and double-side $\delta$-doped InAlSb/InSb quantum wells with varying distances down to 50 nm to the surface on GaSb metamorphic buffers. We analyze the surface morphology as well as the…

Nanoscale diffusion at the interfaces in multilayers plays a vital role in controlling their physical properties for a variety of applications. In the present work depth-dependent interdiffusion in a Si/Fe/Si trilayer has been studied with…

In this work, we study the impact that random alloy fluctuations have on the distribution of electrons and holes across the active region of a (In,Ga)N/GaN multi-quantum well based light emitting diode (LED). To do so, an atomistic…

Slow magnetooscilations of the conductivity are observed in a 75 nm wide quantum well at heating of the two-dimensional electrons by a high-intensity surface acoustic wave. These magnetooscillations are caused by intersubband elastic…

Undoped Si-SiGe two-dimensional electron gas (2DEG) provide an ideal platform for hosting quantum-dot spin-qubits owing enhanced spin dephasing times and compatibility with standard CMOS technology. The strained Si quantum well reduces the…

We report on two sub-band transport in double gate SiO$_2$-Si-SiO$_2$ quantum well with 14 nm thick Si layer at 270 mK. At symmetric well potential the experimental sub-band spacing changes monotonically from 2.3 to 0.3 meV when the total…

: n-type Ge/SiGe asymmetric-coupled quantum wells represent the building block of a variety of nanoscale quantum devices, including recently proposed designs for a silicon-based THz quantum cascade laser. In this paper, we combine…