Spin-orbit coupling and operation of multivalley spin qubits

M. Veldhorst, R. Ruskov, C. H. Yang, J. C C Hwang, F. E. Hudson, M. E. Flatté, C. Tahan, Kohei M Itoh, A. Morello, A. S. Dzurak

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Spin qubits composed of either one or three electrons are realized in a quantum dot formed at a Si/SiO2 interface in isotopically enriched silicon. Using pulsed electron-spin resonance, we perform coherent control of both types of qubits, addressing them via an electric field dependent g factor. We perform randomized benchmarking and find that both qubits can be operated with high fidelity. Surprisingly, we find that the g factors of the one-electron and three-electron qubits have an approximately linear but opposite dependence as a function of the applied dc electric field. We develop a theory to explain this g-factor behavior based on the spin-valley coupling that results from the sharp interface. The outer "shell" electron in the three-electron qubit exists in the higher of the two available conduction-band valley states, in contrast with the one-electron case, where the electron is in the lower valley. We formulate a modified effective mass theory and propose that intervalley spin-flip tunneling dominates over intravalley spin flips in this system, leading to a direct correlation between the spin-orbit coupling parameters and the g factors in the two valleys. In addition to offering all-electrical tuning for single-qubit gates, the g-factor physics revealed here for one-electron and three-electron qubits offers potential opportunities for different qubit control approaches.

Original languageEnglish
Article number201401
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume92
Issue number20
DOIs
Publication statusPublished - 2015 Nov 5

Fingerprint

Orbits
orbits
Electrons
electrons
valleys
Electric fields
approach control
electric fields
Silicon
Benchmarking
Conduction bands
Semiconductor quantum dots
Paramagnetic resonance
electron paramagnetic resonance
conduction bands
Physics
Tuning
tuning
quantum dots
physics

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Veldhorst, M., Ruskov, R., Yang, C. H., Hwang, J. C. C., Hudson, F. E., Flatté, M. E., ... Dzurak, A. S. (2015). Spin-orbit coupling and operation of multivalley spin qubits. Physical Review B - Condensed Matter and Materials Physics, 92(20), [201401]. https://doi.org/10.1103/PhysRevB.92.201401

Spin-orbit coupling and operation of multivalley spin qubits. / Veldhorst, M.; Ruskov, R.; Yang, C. H.; Hwang, J. C C; Hudson, F. E.; Flatté, M. E.; Tahan, C.; Itoh, Kohei M; Morello, A.; Dzurak, A. S.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 92, No. 20, 201401, 05.11.2015.

Research output: Contribution to journalArticle

Veldhorst, M, Ruskov, R, Yang, CH, Hwang, JCC, Hudson, FE, Flatté, ME, Tahan, C, Itoh, KM, Morello, A & Dzurak, AS 2015, 'Spin-orbit coupling and operation of multivalley spin qubits', Physical Review B - Condensed Matter and Materials Physics, vol. 92, no. 20, 201401. https://doi.org/10.1103/PhysRevB.92.201401
Veldhorst, M. ; Ruskov, R. ; Yang, C. H. ; Hwang, J. C C ; Hudson, F. E. ; Flatté, M. E. ; Tahan, C. ; Itoh, Kohei M ; Morello, A. ; Dzurak, A. S. / Spin-orbit coupling and operation of multivalley spin qubits. In: Physical Review B - Condensed Matter and Materials Physics. 2015 ; Vol. 92, No. 20.
@article{5783c742a48444e7a8bb3e4c1df7532c,
title = "Spin-orbit coupling and operation of multivalley spin qubits",
abstract = "Spin qubits composed of either one or three electrons are realized in a quantum dot formed at a Si/SiO2 interface in isotopically enriched silicon. Using pulsed electron-spin resonance, we perform coherent control of both types of qubits, addressing them via an electric field dependent g factor. We perform randomized benchmarking and find that both qubits can be operated with high fidelity. Surprisingly, we find that the g factors of the one-electron and three-electron qubits have an approximately linear but opposite dependence as a function of the applied dc electric field. We develop a theory to explain this g-factor behavior based on the spin-valley coupling that results from the sharp interface. The outer {"}shell{"} electron in the three-electron qubit exists in the higher of the two available conduction-band valley states, in contrast with the one-electron case, where the electron is in the lower valley. We formulate a modified effective mass theory and propose that intervalley spin-flip tunneling dominates over intravalley spin flips in this system, leading to a direct correlation between the spin-orbit coupling parameters and the g factors in the two valleys. In addition to offering all-electrical tuning for single-qubit gates, the g-factor physics revealed here for one-electron and three-electron qubits offers potential opportunities for different qubit control approaches.",
author = "M. Veldhorst and R. Ruskov and Yang, {C. H.} and Hwang, {J. C C} and Hudson, {F. E.} and Flatt{\'e}, {M. E.} and C. Tahan and Itoh, {Kohei M} and A. Morello and Dzurak, {A. S.}",
year = "2015",
month = "11",
day = "5",
doi = "10.1103/PhysRevB.92.201401",
language = "English",
volume = "92",
journal = "Physical Review B-Condensed Matter",
issn = "1098-0121",
publisher = "American Physical Society",
number = "20",

}

TY - JOUR

T1 - Spin-orbit coupling and operation of multivalley spin qubits

AU - Veldhorst, M.

AU - Ruskov, R.

AU - Yang, C. H.

AU - Hwang, J. C C

AU - Hudson, F. E.

AU - Flatté, M. E.

AU - Tahan, C.

AU - Itoh, Kohei M

AU - Morello, A.

AU - Dzurak, A. S.

PY - 2015/11/5

Y1 - 2015/11/5

N2 - Spin qubits composed of either one or three electrons are realized in a quantum dot formed at a Si/SiO2 interface in isotopically enriched silicon. Using pulsed electron-spin resonance, we perform coherent control of both types of qubits, addressing them via an electric field dependent g factor. We perform randomized benchmarking and find that both qubits can be operated with high fidelity. Surprisingly, we find that the g factors of the one-electron and three-electron qubits have an approximately linear but opposite dependence as a function of the applied dc electric field. We develop a theory to explain this g-factor behavior based on the spin-valley coupling that results from the sharp interface. The outer "shell" electron in the three-electron qubit exists in the higher of the two available conduction-band valley states, in contrast with the one-electron case, where the electron is in the lower valley. We formulate a modified effective mass theory and propose that intervalley spin-flip tunneling dominates over intravalley spin flips in this system, leading to a direct correlation between the spin-orbit coupling parameters and the g factors in the two valleys. In addition to offering all-electrical tuning for single-qubit gates, the g-factor physics revealed here for one-electron and three-electron qubits offers potential opportunities for different qubit control approaches.

AB - Spin qubits composed of either one or three electrons are realized in a quantum dot formed at a Si/SiO2 interface in isotopically enriched silicon. Using pulsed electron-spin resonance, we perform coherent control of both types of qubits, addressing them via an electric field dependent g factor. We perform randomized benchmarking and find that both qubits can be operated with high fidelity. Surprisingly, we find that the g factors of the one-electron and three-electron qubits have an approximately linear but opposite dependence as a function of the applied dc electric field. We develop a theory to explain this g-factor behavior based on the spin-valley coupling that results from the sharp interface. The outer "shell" electron in the three-electron qubit exists in the higher of the two available conduction-band valley states, in contrast with the one-electron case, where the electron is in the lower valley. We formulate a modified effective mass theory and propose that intervalley spin-flip tunneling dominates over intravalley spin flips in this system, leading to a direct correlation between the spin-orbit coupling parameters and the g factors in the two valleys. In addition to offering all-electrical tuning for single-qubit gates, the g-factor physics revealed here for one-electron and three-electron qubits offers potential opportunities for different qubit control approaches.

UR - http://www.scopus.com/inward/record.url?scp=84949545236&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84949545236&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.92.201401

DO - 10.1103/PhysRevB.92.201401

M3 - Article

AN - SCOPUS:84949545236

VL - 92

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 20

M1 - 201401

ER -