Related papers: Increasing valley splitting in Si/SiGe by practica…
Orbital degeneracy of the electronic conduction band edge in silicon is a potential roadblock to the storage and manipulation of quantum information involving the electronic spin degree of freedom in this host material. This difficulty may…
As silicon spin qubit chips are increasing in qubit number and area, methods for the screening of qubit related material parameters become vital. Here we demonstrate the two-dimensional mapping of small variations of the electron g-factor…
Electrons confined in silicon quantum dots exhibit orbital, spin, and valley degrees of freedom. The valley degree of freedom originates from the bulk bandstructure of silicon, which has six degenerate electronic minima. The degeneracy can…
Silicon-based metal-oxide-semiconductor quantum dots are prominent candidates for high-fidelity, manufacturable qubits. Due to silicon's band structure, additional low-energy states persist in these devices, presenting both challenges and…
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 $\nu=3$…
The electrical characterisation of classical and quantum devices is a critical step in the development cycle of heterogeneous material stacks for semiconductor spin qubits. In the case of silicon, properties such as disorder and energy…
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,…
To date, a number of valley materials have been discovered with the spin-valley or valley-layer couplings. It is highly desirable to realize the interplay of more electronic degrees of freedom in a valley material. Based on the…
The bid for scalable physical qubits has attracted many possible candidate platforms. In particular, spin-based qubits in solid-state form factors are attractive as they could potentially benefit from processes similar to those used for…
Valley-orbit coupling is a key parameter for a silicon quantum dot in determining its suitability for applications in quantum information processing. In this paper we study the effect of interface steps on the magnitude and phase of…
Silicon quantum dot qubits must contend with low-lying valley excited states which are sensitive functions of the quantum well heterostructure and disorder; quantifying and maximizing the energies of these states are critical to improving…
Ge/SiGe multi-quantum well heterostructures are highly sought-after for silicon-integrated optoelectronic devices operating in the broad range of the electromagnetic spectrum covering infrared to terahertz wavelengths. However, the…
SiGe heteroepitaxial growth yields pristine host material for quantum dot qubits, but residual interface disorder can lead to qubit-to-qubit variability that might pose an obstacle to reliable SiGe-based quantum computing. We demonstrate a…
Two-dimensional semiconductors feature valleytronics phenomena due to locking of the spin and momentum valley of the electrons. However, the valley polarization is intrinsically limited in monolayer crystals by the fast intervalley…
In the research of topological phases of matter, valley pseudospins have been introduced into photonic systems. Here, we construct a split-ring photonic crystal (SPC) in which the spilt rings are distributed according to the Kagome model.…
We report novel manifestation of the valley splitting for the two valley electron system in (100) Si-inversion layers at low carrier density. We found that valley splitting causes almost 100% modulation of the Shubnikov de Haas oscillations…
Engineering conduction-band valley couplings is a key challenge for Si-based spin qubits. Recent work has shown that the most reliable method for enhancing valley couplings entails adding Ge concentration oscillations to the quantum well.…
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…
(001) Si spin qubits are being intensively studied because they have structures similar to that of CMOS devices currently being produced, and thus have the advantage of utilizing state-of-the-art miniaturization, integration, and…
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…