English
Related papers

Related papers: Switching between relaxation hotspots and coldspot…

200 papers

We investigate the singlet-triplet relaxation due to the spin-orbit coupling together with the electron-phonon scattering in two-electron multivalley silicon single quantum dots, using the exact diagonalization method and the Fermi golden…

Mesoscale and Nanoscale Physics · Physics 2010-06-30 L. Wang , K. Shen , B. Y. Sun , M. W. Wu

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

We present a rigorous method to reduce the three-dimensional (3D) description of a quantum dot in silicon to an effective two-dimensional (2D) envelope function theory for electron spin qubits. By systematically integrating out the strongly…

Quantum Physics · Physics 2025-09-30 Christian W. Binder , Guido Burkard , Andrew J. Fisher

Si/SiGe heterostructures on bulk Si substrates have been shown to host high fidelity electron spin qubits. Building a scalable quantum processor would, however, benefit from further improvement of critical material properties such as the…

Mesoscale and Nanoscale Physics · Physics 2026-01-29 Lucas Marcogliese , Ouviyan Sabapathy , Rudolf Richter , Jhih-Sian Tu , Dominique Bougeard , Lars R. Schreiber

In silicon quantum dots (QDs), at a certain magnetic field commonly referred to as the "hot spot", the electron spin relaxation rate (T_1^(-1)) can be drastically enhanced due to strong spin-valley mixing. Here, we experimentally find that…

Spin-orbit effects, inherent to electrons confined in quantum dots at a silicon heterointerface, provide a means to control electron spin qubits without the added complexity of on-chip, nanofabricated micromagnets or nearby coplanar…

Mesoscale and Nanoscale Physics · Physics 2022-02-04 Ryan M. Jock , N. Tobias Jacobson , Martin Rudolph , Daniel R. Ward , Malcolm S. Carroll , Dwight R. Luhman

We study all of the leading-order contributions to spin relaxation of \textit{conduction} electrons in silicon due to the electron-phonon interaction. Using group theory, $k\cdot p$ perturbation method and rigid-ion model, we derive an…

Materials Science · Physics 2013-05-21 Yang Song , Hanan Dery

We describe dynamics of spin and valley transitions driven by alternating electric fields in quantum dots defined electrostatically within semiconducting carbon nanotubes (CNT). We use the tight-binding approach to describe the states…

Mesoscale and Nanoscale Physics · Physics 2014-09-04 E. N. Osika , A. Mreńca , B. Szafran

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…

We develop a microscopic and atomistic theory of electron spin-based qubits in gated quantum dots in a single layer of transition metal dichalcogenides. The qubits are identified with two degenerate locked spin and valley states in a gated…

Mesoscale and Nanoscale Physics · Physics 2021-11-24 Abdulmenaf Altıntaş , Maciej Bieniek , Amintor Dusko , Marek Korkusiński , Jarosław Pawłowski , Paweł Hawrylak

In the "flopping-mode" regime of electron spin resonance, a single electron confined in a double quantum dot is electrically driven in the presence of a magnetic field gradient. The increased dipole moment of the charge in the flopping mode…

Mesoscale and Nanoscale Physics · Physics 2025-03-14 Steve M. Young , Mitchell Brickson , Jason R. Petta , N. Tobias Jacobson

(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…

Quantum Physics · Physics 2025-01-24 Takafumi Tokunaga , Hiromichi Nakazato

The conduction band degeneracy in Si is detrimental to quantum computing based on spin qubits, for which a nondegenerate ground orbital state is desirable. This degeneracy is lifted at an interface with an insulator as the spatially abrupt…

Materials Science · Physics 2009-08-31 A. L. Saraiva , M. J. Calderón , Xuedong Hu , S. Das Sarma , Belita Koiller

Controlling electron spins in double quantum dots allows individual electrons to be trapped and manipulated for next-generation solid-state qubit devices. In this paper, the study analyzes spin relaxation due to deformation potentials of…

Mesoscale and Nanoscale Physics · Physics 2026-05-19 Sanjay Prabhakar

Non-adiabatic quantum effects, often experimentally observed in semiconductors nano-devices such as single-electron pumps operating at high frequencies, can result in undesirable and uncontrollable behaviour. However, when combined with the…

Mesoscale and Nanoscale Physics · Physics 2022-02-16 Alan Gardin , Ross D. Monaghan , Tyler Whittaker , Rajib Rahman , Giuseppe C. Tettamanzi

We fabricated Quantum Dot (QD) devices using a standard SOI CMOS process flow, and demonstrated that the spin of confined electrons could be controlled via a local electrical-field excitation, owing to inter-valley spin-orbit coupling. We…

Divacancy spins in silicon carbide implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host. On the other hand, there are still numerous open questions about the physics of divacancy point…

Mesoscale and Nanoscale Physics · Physics 2021-09-29 Oscar Bulancea Lindvall , Nguyen Tien Son , Igor A. Abrikosov , Viktor Ivády

We study theoretically the phonon-induced relaxation and decoherence processes in the hybrid qubit in silicon. Hybrid qubit behaves as a charge qubit when the detuning is close to zero and as spin qubit for large detuning values. It is…

Quantum Physics · Physics 2019-07-24 E. Ferraro , M. Fanciulli , M. De Michielis

Many efforts have succeeded over the last decade at lengthening the timescale in which spin qubits loss quantum information under free evolution. With these design principles at a mature stage, it is now timely to widen the scope and take…

Quantum Physics · Physics 2024-07-31 Luis Escalera-Moreno

Pioneering studies in transition metal dichalcogenides have demonstrated convincingly the co-existence of multiple angular momentum degrees of freedom -- of spin (1/2 $s_z = \pm 1/2$), valley ($\tau = K, K'$ or $\pm 1$), and atomic orbital…

Mesoscale and Nanoscale Physics · Physics 2020-01-28 Feng-Wu Chen , Yu-Shu Wu