Related papers: Valley Splitting Correlations Across a Silicon Qua…
We report the demonstration of a low-disorder silicon metal-oxide-semiconductor (Si MOS) quantum dot containing a tunable number of electrons from zero to N=27. The observed evolution of addition energies with parallel magnetic field…
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…
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…
We determine the energy splitting of the conduction-band valleys in two-dimensional (2D) electrons confined in silicon metal oxide semiconductor (Si-MOS) Hall-bar transistors. These Si-MOS Hall bars are made by advanced semiconductor…
The valley degeneracy in Si qubit devices presents problems for their use in quantum information processing. It is possible to lift this degeneracy by using the Wiggle Well architecture, in which an oscillatory Ge concentration couples the…
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…
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 have investigated the valley splitting of two-dimensional electrons in high quality Si/Si$_{1-x}$Ge$_x$ heterostructures under tilted magnetic fields. For all the samples in our study, the valley splitting at filling factor $\nu=3$…
Interactions between electrons can strongly affect the shape and functionality of multi-electron quantum dots. The resulting charge distributions can be localized, as in the case of Wigner molecules, with consequences for the energy…
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…
While bulk silicon has long been understood to exhibit relatively weak spin-orbit coupling (SOC), confinement of electrons to quantum dots (QDs) at a silicon heterointerface results in significantly larger SOC. This is a concern for…
The coupling between $z$ valleys in the conduction band of a Si quantum well arises from phenomena occurring within several atoms from the interface, thus ruling out a theoretical description based on pure effective mass theory. However,…
We compute valley splittings in Si/SiGe superlattices using ab initio density functional theory (DFT). This first-principle approach is expected to provide an excellent description of interfaces, strains, and atomistic disorder without…
An important challenge in silicon quantum electronics in the few electron regime is the potentially small energy gap between the ground and excited orbital states in 3D quantum confined nanostructures due to the multiple valley degeneracies…
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…
In Si quantum dot systems, large magnetic field gradients are needed to implement spin rotations via electric dipole spin resonance (EDSR). By increasing the effective electron dipole, flopping mode qubits can provide faster gates with…
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…
Electrons and holes confined in quantum dots define an excellent building block for quantum emergence, simulation, and computation. In order for quantum electronics to become practical, large numbers of quantum dots will be required,…
Semiconductor spin qubits have gained increasing attention as a possible platform to host a fault-tolerant quantum computer. First demonstrations of spin qubit arrays have been shown in a wide variety of semiconductor materials. The highest…
Effect of electric field on spin splitting in SiGe quantum wells (QWs) has been studied theoretically. Microscopical calculations of valley and spin splittings are performed in the effective $sp^3d^5s^*$ tight-binding model. The splittings…