Hole spin relaxation in Ge–Si core–shell nanowire qubits
Source abstract
Abstract
Controlling decoherence is the biggest challenge in efforts to develop quantum information hardware. Single electron spins in gallium arsenide are a leading candidate among implementations of solid-state quantum bits, but their strong coupling to nuclear spins produces high decoherence rates. Group IV semiconductors, on the other hand, have relatively low nuclear spin densities, making them an attractive platform for spin quantum bits. However, device fabrication remains a challenge, particularly with respect to the control of materials and interfaces. Here, we demonstrate state preparation, pulsed gate control and charge-sensing spin readout of hole spins confined in a Ge-Si core-shell nanowire. With fast gating, we measure T(1) spin relaxation times of up to 0.6 ms in coupled quantum dots at zero magnetic field. Relaxation time increases as the magnetic field is reduced, which is consistent with a spin-orbit mechanism that is usually masked by hyperfine contributions.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Quantum and electron transport phenomena · Semiconductor materials and devices · Advancements in Semiconductor Devices and Circuit Design
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (39)
Show source-provided references
1. Loss, D. & DiVincenzo, D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120–126 (1998).10.1103/PhysRevA.57.120 ↗
2. Hanson, R. & Awschalom, D. Coherent manipulation of single spins in semiconductors. Nature 453, 1043–1049 (2008).10.1038/nature07129 ↗
3. Petta, J. R., Lu, H. & Gossard, A. C. A coherent beam splitter for electronic spin states. Science 327, 669–672 (2010).10.1126/science.1183628 ↗
4. Khaetskii, A. V., Loss, D. & Glazman, L. Electron spin decoherence in quantum dots due to interaction with nuclei. Phys. Rev. Lett. 88, 186802 (2002).10.1103/PhysRevLett.88.186802 ↗
5. Johnson, A. et al. Triplet–singlet spin relaxation via nuclei in a double quantum dot. Nature 435, 925–928 (2005).10.1038/nature03815 ↗
6. Petta, J. et al. Coherent manipulation of coupled electron spins in semiconductor quantum dots. Science 309, 2180–2184 (2005).10.1126/science.1116955 ↗
7. Dyakonov, M. I. (ed.) Spin Physics in Semiconductors (Springer Series in Solid-State Sciences 157, Springer, 2008).10.1007/978-3-540-78820-1 ↗
8. Elzerman, J. M. et al. Single-shot read-out of an individual electron spin in a quantum dot. Nature 430, 431–435 (2004).10.1038/nature02693 ↗
9. Koppens, F., Buizert, C., Tielrooij, K. & Vink, I. Driven coherent oscillations of a single electron spin in a quantum dot. Nature 442, 766–771 (2006).10.1038/nature05065 ↗
10. Nowack, K., Koppens, F. & Nazarov, Y. Coherent control of a single electron spin with electric fields. Science 318, 1430–1433 (2007).10.1126/science.1148092 ↗
11. Bluhm, H. et al. Dephasing time of GaAs electron–spin qubits coupled to a nuclear bath exceeding 200 µs. Nature Phys. 7, 109–113 (2011).10.1038/nphys1856 ↗
12. Foletti, S., Bluhm, H., Mahalu, D., Umansky, V. & Yacoby, A. Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization. Nature Phys. 5, 903–908 (2009).10.1038/nphys1424 ↗
13. Trauzettel, B., Bulaev, D. V., Loss, D. & Burkard, G. Spin qubits in graphene quantum dots. Nature Phys. 3, 192–196 (2007).10.1038/nphys544 ↗
14. Kloeffel, C., Trif, M. & Loss, D. Strong spin–orbit interaction and helical hole states in Ge/Si nanowires. Phys. Rev. B 84, 195314 (2011).10.1103/PhysRevB.84.195314 ↗
15. Mason, N., Biercuk, M. & Marcus, C. Local gate control of a carbon nanotube double quantum dot. Science 303, 655–658 (2004).10.1126/science.1093605 ↗
16. Hu, Y. et al. A Ge/Si heterostructure nanowire-based double quantum dot with integrated charge sensor. Nature Nanotech. 2, 622–625 (2007).10.1038/nnano.2007.302 ↗
17. Steele, G. A., Gotz, G. & Kouwenhoven, L. P. Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes. Nature Nanotech. 4, 363–367 (2009).10.1038/nnano.2009.71 ↗
18. Shaji, N. et al. Spin blockade and lifetime-enhanced transport in a few-electron Si/SiGe double quantum dot. Nature Phys. 4, 540–544 (2008).10.1038/nphys988 ↗
19. Katsaros, G. et al. Hybrid superconductor–semiconductor devices made from self-assembled SiGe nanocrystals on silicon. Nature Nanotech. 5, 458–464 (2010).10.1038/nnano.2010.84 ↗
20. Zwanenburg, F. A., van Rijmenam, C., Fang, Y., Lieber, C. M. & Kouwenhoven, L. P. Spin states of the first four holes in a silicon nanowire quantum dot. Nano Lett. 9, 1071–1079 (2009).10.1021/nl803440s ↗
21. Xiao, M., House, M. G. & Jiang, H. W. Measurement of the spin relaxation time of single electrons in a silicon metal-oxide–semiconductor-based quantum dot. Phys. Rev. Lett. 104, 096801 (2010).10.1103/PhysRevLett.104.096801 ↗
22. Simmons, C. B. et al. Tunable spin loading and T1 of a silicon spin qubit measured by single-shot readout. Phys. Rev. Lett. 106, 156804 (2011).10.1103/PhysRevLett.106.156804 ↗
23. Hayes, R. R. et al. Lifetime measurements T1 of electron spins in Si/SiGe quantum dots. Preprint at arXiv:0908.0173v1 (2009).
24. Borselli, M. G. et al. Pauli spin blockade in undoped Si/SiGe two-electron quantum dots. Appl. Phys. Lett. 99, 063109 (2011).10.1063/1.3623479 ↗
25. Hanson, R., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spins in few-electron quantum dots. Rev. Mod. Phys. 79, 1217–1265 (2007).10.1103/RevModPhys.79.1217 ↗
26. Lieber, C. & Wang, Z. Functional nanowires. MRS Bull. 32, 99–108 (2007).10.1557/mrs2007.41 ↗
27. Lu, W., Xiang, J., Timko, B., Wu, Y. & Lieber, C. One-dimensional hole gas in germanium/silicon nanowire heterostructures. Proc. Natl Acad. Sci. USA 102, 10046–10051 (2005).10.1073/pnas.0504581102 ↗
28. Zulicke, U. & Csontos, D. Zeeman splitting in cylindrical hole quantum wires. Curr. Appl. Phys. 8, 237–240 (2008).10.1016/j.cap.2007.10.005 ↗
29. Nenashev, A. V., Dvurechenskii, A. V. & Zinovieva, A. F. Wave functions and g factor of holes in Ge/Si quantum dots. Phys. Rev. B 67, 205301 (2003).10.1103/PhysRevB.67.205301 ↗
30. Zhong, Z. H., Fang, Y., Lu, W. & Lieber, C. M. Coherent single charge transport in molecular-scale silicon nanowires. Nano Lett. 5, 1143–1146 (2005).10.1021/nl050783s ↗
31. Roddaro, S. et al. Spin states of holes in Ge/Si nanowire quantum dots. Phys. Rev. Lett. 101, 186802 (2008).10.1103/PhysRevLett.101.186802 ↗
32. Wang, L., Shen, K., Sun, B. Y. & Wu, M. W. Singlet–triplet relaxation in multivalley silicon single quantum dots. Phys. Rev. B 81, 235326 (2010).10.1103/PhysRevB.81.235326 ↗
33. Trif, M., Simon, P. & Loss, D. Relaxation of hole spins in quantum dots via two-phonon processes. Phys. Rev. Lett. 103, 106601 (2009).10.1103/PhysRevLett.103.106601 ↗
34. Levitov, L. S. & Rashba, E. I. Dynamical spin–electric coupling in a quantum dot. Phys. Rev. B 67, 115324 (2003).10.1103/PhysRevB.67.115324 ↗
35. Shankar, S., Tyryshkin, A., He, J. & Lyon, S. Spin relaxation and coherence times for electrons at the Si/SiO2 interface. Phys. Rev. B 82, 195323 (2010).10.1103/PhysRevB.82.195323 ↗
36. Winkler, R. in Spin–Orbit Coupling Effects in Two-Dimensional Electron and Hole Systems Ch. 3, 28 (Springer Tracts in Modern Physics 191, Springer, 2003).10.1007/b13586 ↗
37. Hao, X. J. et al. Strong and tunable spin–orbit coupling of one-dimensional holes in Ge/Si core/shell nanowires. Nano Lett. 10, 2956–2960 (2010).10.1021/nl101181e ↗
38. Nadj-Perge, S., Frolov, S. M., Bakkers, E. P. A. M. & Kouwenhoven, L. P. Spin–orbit qubit in a semiconductor nanowire. Nature 468, 1084–1087 (2010).10.1038/nature09682 ↗
39. Tang, J-M., Levy, J. & Flatté, M. E. All-electrical control of single ion spins in a semiconductor. Phys. Rev. Lett. 97, 106803 (2006).10.1103/PhysRevLett.97.106803 ↗