English
Related papers

Related papers: Valley splitting in Si quantum dots embedded in Si…

200 papers

Research on Si quantum dot spin qubits is motivated by the long spin coherence times measured in Si, yet the orbital spectrum of Si dots is increased as a result of the valley degree of freedom. The valley degeneracy may be lifted by the…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Dimitrie Culcer , Lukasz Cywinski , Qiuzi Li , Xuedong Hu , S. Das Sarma

Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochastic shifts of electron's wavefunction lead to fluctuations of…

Mesoscale and Nanoscale Physics · Physics 2024-08-09 Marcin Kępa , Łukasz Cywiński , Jan A. Krzywda

Interface states in a silicon/barrier junction break the silicon valley degeneracy near the interface, a desirable feature for some Si quantum electronics applications. Within a minimal multivalley tight-binding model in one dimension, we…

Mesoscale and Nanoscale Physics · Physics 2014-05-23 Amintor Dusko , A. L. Saraiva , Belita Koiller

The authors investigate the magnetic field dependence of the energy splitting between low-lying valley states for electrons in a Si/SiGe quantum well tilted with respect to the crystallographic axis. The presence of atomic steps at the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mark Friesen , M. A. Eriksson , S. N. Coppersmith

The lifting of the two-fold degeneracy of the conduction valleys in a strained silicon quantum well is critical for spin quantum computing. Here, we obtain an accurate measurement of the splitting of the valley states in the low-field…

The presence of valley states is a significant obstacle to realizing quantum information technologies in Silicon quantum dots, as leakage into alternate valley states can introduce errors into the computation. We use a perturbative…

Mesoscale and Nanoscale Physics · Physics 2022-01-25 Donovan Buterakos , Sankar Das Sarma

Valley splitting in strained Si/SiGe quantum wells is a central parameter for silicon spin qubits and is commonly described with envelope-function and effective-mass theories. These models provide a computationally efficient continuum…

Mesoscale and Nanoscale Physics · Physics 2026-02-17 Lasse Ermoneit , Abel Thayil , Thomas Koprucki , Markus Kantner

The valley splitting in Si two-dimensional electron systems is studied using Si/SiGe single quantum wells (QWs) with different well widths. The energy gaps for 4 and 5.3 nm QWs, obtained from the temperature dependence of the longitudinal…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Kohei Sasaki , Ryuichi Masutomi , Kiyohiko Toyama , Kentarou Sawano , Yasuhiro Shiraki , Tohru Okamoto

The valley splitting of 2D electrons in doubly-gated silicon-on-insulator quantum wells is studied by low temperature transport measurements under magnetic fields. At the buried thermal-oxide SiO$_{2}$ interface, the valley splitting…

Mesoscale and Nanoscale Physics · Physics 2025-09-03 Nathan Aubergier , Vincent T. Renard , Sylvain Barraud , Kei Takashina , Benjamin A. Piot

Regardless of various material design strategies, experimentally achieving substantial and controllable valley splitting in Si/SiGe quantum wells remains a central challenge for ensuring high gate uniformity. This difficulty arises from…

Mesoscale and Nanoscale Physics · Physics 2025-12-01 Yang Liu , Gang Wang , Shan Guan , Jun-Wei Luo , Shu-Shen Li

Quantum dots in silicon are promising candidates for implementation of solid-state quantum information processing. It is important to understand the effects of the multiple conduction band valleys of silicon on the properties of these…

Mesoscale and Nanoscale Physics · Physics 2013-08-27 John King Gamble , M. A. Eriksson , S. N. Coppersmith , Mark Friesen

A detailed understanding of the material properties that affect the splitting between the two low-lying valley states in Si/SiGe heterostructures will be increasingly important as the number of spin qubits is increased. Scanning gate…

Mesoscale and Nanoscale Physics · Physics 2024-10-04 Efe Cakar , H. Ekmel Ercan , Gordian Fuchs , Artem O. Denisov , Christopher R. Anderson , Mark F. Gyure , Jason R. Petta

Spin qubit shuttling via moving conveyor-mode quantum dots in Si/SiGe offers a promising route to scalable miniaturized quantum computing. Recent modeling of dephasing via valley degrees of freedom and well disorder dictate a slow shutting…

Understanding crystal characteristics down to the atomistic level increasingly emerges as a crucial insight for creating solid state platforms for qubits with reproducible and homogeneous properties. Here, isotope composition depth profiles…

The valley splitting, which lifts the degeneracy of the lowest two valley states in a SiO$_2$/(100)Si/SiO$_2$ quantum well is examined through transport measurements. We demonstrate that the valley splitting can be observed directly as a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 K. Takashina , Y. Ono , A. Fujiwara , Y. Takahashi , Y. Hirayama

Electrons confined in Si quantum dots possess orbital, spin, and valley degrees of freedom (d.o.f.). We perform Landau-Zener-Stuckelberg-Majorana (LZSM) interferometry on a Si double quantum dot that is strongly coupled to a microwave…

Mesoscale and Nanoscale Physics · Physics 2018-10-17 X. Mi , S. Kohler , J. R. Petta

The valley splitting of the first few Landau levels is calculated as a function of the magnetic field for electrons confined in a strained silicon quantum well grown on a tilted SiGe substrate, using a parameterized tight-binding method.…

Materials Science · Physics 2009-11-11 Seungwon Lee , Paul von Allmen

Enhancing valley splitting in SiGe heterostructures is a crucial task for developing silicon spin qubits. Complex SiGe heterostructures, sharing a common feature of four-monolayer (4ML) Ge layer next to the silicon quantum well (QW), have…

Mesoscale and Nanoscale Physics · Physics 2022-05-04 Gang Wang , Zhi-Gang Song , Jun-Wei Luo , Shu-Shen Li

We test the valley-filtering capabilities of a quantum dot inscribed by locally straining an $\alpha$-$\mathcal{T}_3$ lattice. Specifically, we consider an out-of-plane Gaussian bump in the center of a four-terminal configuration and…

Mesoscale and Nanoscale Physics · Physics 2021-04-16 Alexander Filusch , Alan R. Bishop , Avadh Saxena , Gerhard Wellein , Holger Fehske

We study an accumulation mode Si/SiGe double quantum dot (DQD) containing a single electron that is dipole coupled to microwave photons in a superconducting cavity. Measurements of the cavity transmission reveal dispersive features due to…

Mesoscale and Nanoscale Physics · Physics 2017-10-26 X. Mi , Csaba G. Peterfalvi , Guido Burkard , J. R. Petta