186 citations · 1k across the 35 of their papers we have counts for
24 papers · 1 filter
Sign-switching of superexchange mediated by few electrons under non-uniform magnetic field
Guo Xuan Chan, Xin Wang
Long range interaction between distant spins is an important building block for the realization of large quantum-dot network in which couplings between pairs of spins can be select…
Theory on electron-phonon spin dehphasing in GaAs multi-electron double quantum dots
Guanjie He, Guo Xuan Chan, Xin Wang
Recent studies reveal that a double-quantum-dot system hosting more than two electrons may be superior in certain aspects as compared to the traditional case in which only two elec…
Universal control of superexchange in linear triple quantum dots with an empty mediator
Guo Xuan Chan, Peihao Huang, Xin Wang
Superexchange is one of the vital resources to realize long-range interaction between distant spins for large-scale quantum computing. Recent experiments have demonstrated coherent…
Microscopic theory on magnetic-field-tuned sweet spot of exchange interactions in multielectron quantum-dot systems
Guo Xuan Chan, Xin Wang
The exchange interaction in a singlet-triplet qubit defined by two-electron states in the double-quantum-dot system ("two-electron singlet-triplet qubit") typically varies monotoni…
Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
Guo Xuan Chan, Xin Wang
The search of a sweet spot, locus in qubit parameters where quantum control is first-order insensitive to noises, is key to achieve high-fidelity quantum gates. Efforts to search f…
Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field
Guo Xuan Chan, Jason P. Kestner, Xin Wang
Charge noise is the main hurdle preventing high-fidelity operation, in particular that of two-qubit gates, of semiconductor-quantum-dot-based spin qubits. While certain sweet spots…
Suppression of leakage for a charge quadrupole qubit in triangular geometry
Guo Xuan Chan, Xin Wang
We present a simple yet effective strategy to suppress the leakage in the charge quadrupole qubit system by having the dots in a triangle as opposed to the linear geometry original…
Tunable charge qubit based on barrier-controlled triple quantum dots
Xu-Chen Yang, Guo Xuan Chan, Xin Wang
We present a theoretical proposal of a tunable charge qubit, hosted in triple quantum dots. The manipulation is solely performed by changing the heights of the two potential barrie…
Leakage and sweet spots in triple-quantum-dot spin qubits: A molecular-orbital study
Chengxian Zhang, Xu-Chen Yang, Xin Wang
A triple-quantum-dot system can be operated as either an exchange-only qubit or a resonant-exchange qubit. While it is generally believed that the decisive advantage of the resonan…
Fast pulse sequences for dynamically corrected gates in single-triplet qubits
Robert E. Throckmorton, Chengxian Zhang, Xu-Chen Yang +3
We present a set of experimentally feasible pulse sequences that implement any single-qubit gate on a singlet-triplet spin qubit and demonstrate that these new sequences are up to…
Magic angle for barrier-controlled double quantum dots
Xu-Chen Yang, Xin Wang
We show that the exchange interaction of a singlet-triplet spin qubit confined in double quantum dots, when being controlled by the barrier method, is insensitive to a charged impu…
Randomized benchmarking of barrier versus tilt control of a singlet-triplet qubit
Chengxian Zhang, Robert E. Throckmorton, Xu-Chen Yang +3
Decoherence due to charge noise is one of the central challenges in using spin qubits in semiconductor quantum dots as a platform for quantum information processing. Recently, it h…
Benchmarking of dynamically corrected gates for the exchange-only spin qubit in noise environment
Chengxian Zhang, Xu-Chen Yang, Xin Wang
We study theoretically the responses of the dynamically corrected gates to time-dependent noises in the exchange-only spin qubit system. We consider noises having spectra pro…
Noise filtering of composite pulses for singlet-triplet qubits
Xu-Chen Yang, Xin Wang
Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors…
Fast control of semiconductor qubits beyond the rotating-wave approximation
Yang Song, J. P. Kestner, Xin Wang +1
We present a theoretical study of single-qubit operations by oscillatory fields on various semiconductor platforms. We explicitly show how to perform faster gate operations by goin…
Improving the gate fidelity of capacitively coupled spin qubits
Xin Wang, Edwin Barnes, S. Das Sarma
Capacitively coupled semiconductor spin qubits hold promise as the building blocks of a scalable quantum computing architecture with long-range coupling between distant qubits. How…
Noise-compensating pulses for electrostatically controlled silicon spin qubits
Xin Wang, Fernando A. Calderon-Vargas, Muhed S. Rana +3
We study the performance of SUPCODE---a family of dynamically correcting pulses designed to cancel simultaneously both Overhauser and charge noise for singlet-triplet spin qubits--…
Robust quantum gates for singlet-triplet spin qubits using composite pulses
Xin Wang, Lev S. Bishop, Edwin Barnes +2
We present a comprehensive theoretical treatment of SUPCODE, a method for generating dynamically corrected quantum gate operations, which are immune to random noise in the environm…
Robust Two-Qubit Gates for Exchange-Coupled Qubits
F. Setiawan, Hoi-Yin Hui, J. P. Kestner +2
We present composite pulse sequences that perform fault-tolerant two-qubit gate operations on exchange-only quantum dot spin qubits in various experimentally relevant geometries. W…
Dynamically corrected gates for an exchange-only qubit
G. T. Hickman, Xin Wang, J. P. Kestner +1
We provide analytical composite pulse sequences that perform dynamical decoupling concurrently with arbitrary rotations for a qubit coded in the spin state of a triple quantum dot.…
Composite pulses for robust universal control of singlet-triplet qubits
Xin Wang, Lev S. Bishop, J. P. Kestner +3
Precise qubit manipulation is fundamental to quantum computing, yet experimental systems generally have stray coupling between the qubit and the environment, which hinders the nece…
Quantum theory of the charge stability diagram of semiconductor double quantum dot systems
Xin Wang, Shuo Yang, S. Das Sarma
We complete our recently introduced theoretical framework treating the double quantum dot system with a generalized form of Hubbard model. The effects of all quantum parameters inv…
Hubbard model description of silicon spin qubits: charge stability diagram and tunnel coupling in Si double quantum dots
S. Das Sarma, Xin Wang, Shuo Yang
We apply the recently introduced Hubbard model approach to quantitatively describe the experimental charge stability diagram and tunnel coupling of silicon double quantum dot syste…
Generic Hubbard model description of semiconductor quantum dot spin qubits
Shuo Yang, Xin Wang, S. Das Sarma
We introduce a Hubbard model as the simple quantum generalization of the classical capacitance circuit model to study semiconductor quantum-dot spin qubits. We prove theoretically…