The sub-band structure of atomically sharp dopant profiles in silicon

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The sub-band structure of atomically sharp dopant profiles in silicon. / Mazzola, Federico; Chen, Chin Yi; Rahman, Rajib; Zhu, Xie Gang; Polley, Craig M.; Balasubramanian, Thiagarajan; King, Phil D.C.; Hofmann, Philip; Miwa, Jill A.; Wells, Justin W.

In: npj Quantum Materials, Vol. 5, No. 1, 34, 2020.

Research output: Contribution to journalArticle

Harvard

Mazzola, F, Chen, CY, Rahman, R, Zhu, XG, Polley, CM, Balasubramanian, T, King, PDC, Hofmann, P, Miwa, JA & Wells, JW 2020, 'The sub-band structure of atomically sharp dopant profiles in silicon', npj Quantum Materials, vol. 5, no. 1, 34. https://doi.org/10.1038/s41535-020-0237-1

APA

Mazzola, F., Chen, C. Y., Rahman, R., Zhu, X. G., Polley, C. M., Balasubramanian, T., ... Wells, J. W. (2020). The sub-band structure of atomically sharp dopant profiles in silicon. npj Quantum Materials, 5(1), [34]. https://doi.org/10.1038/s41535-020-0237-1

CBE

Mazzola F, Chen CY, Rahman R, Zhu XG, Polley CM, Balasubramanian T, King PDC, Hofmann P, Miwa JA, Wells JW. 2020. The sub-band structure of atomically sharp dopant profiles in silicon. npj Quantum Materials. 5(1). https://doi.org/10.1038/s41535-020-0237-1

MLA

Vancouver

Author

Mazzola, Federico ; Chen, Chin Yi ; Rahman, Rajib ; Zhu, Xie Gang ; Polley, Craig M. ; Balasubramanian, Thiagarajan ; King, Phil D.C. ; Hofmann, Philip ; Miwa, Jill A. ; Wells, Justin W. / The sub-band structure of atomically sharp dopant profiles in silicon. In: npj Quantum Materials. 2020 ; Vol. 5, No. 1.

RIS

TY - JOUR

T1 - The sub-band structure of atomically sharp dopant profiles in silicon

AU - Mazzola, Federico

AU - Chen, Chin Yi

AU - Rahman, Rajib

AU - Zhu, Xie Gang

AU - Polley, Craig M.

AU - Balasubramanian, Thiagarajan

AU - King, Phil D.C.

AU - Hofmann, Philip

AU - Miwa, Jill A.

AU - Wells, Justin W.

PY - 2020

Y1 - 2020

N2 - The downscaling of silicon-based structures and proto-devices has now reached the single-atom scale, representing an important milestone for the development of a silicon-based quantum computer. One especially notable platform for atomic-scale device fabrication is the so-called Si:P δ-layer, consisting of an ultra-dense and sharp layer of dopants within a semiconductor host. Whilst several alternatives exist, it is on the Si:P platform that many quantum proto-devices have been successfully demonstrated. Motivated by this, both calculations and experiments have been dedicated to understanding the electronic structure of the Si:P δ-layer platform. In this work, we use high-resolution angle-resolved photoemission spectroscopy to reveal the structure of the electronic states which exist because of the high dopant density of the Si:P δ-layer. In contrast to published theoretical work, we resolve three distinct bands, the most occupied of which shows a large anisotropy and significant deviation from simple parabolic behaviour. We investigate the possible origins of this fine structure, and conclude that it is primarily a consequence of the dielectric constant being large (ca. double that of bulk Si). Incorporating this factor into tight-binding calculations leads to a major revision of band structure; specifically, the existence of a third band, the separation of the bands, and the departure from purely parabolic behaviour. This new understanding of the band structure has important implications for quantum proto-devices which are built on the Si:P δ-layer platform.

AB - The downscaling of silicon-based structures and proto-devices has now reached the single-atom scale, representing an important milestone for the development of a silicon-based quantum computer. One especially notable platform for atomic-scale device fabrication is the so-called Si:P δ-layer, consisting of an ultra-dense and sharp layer of dopants within a semiconductor host. Whilst several alternatives exist, it is on the Si:P platform that many quantum proto-devices have been successfully demonstrated. Motivated by this, both calculations and experiments have been dedicated to understanding the electronic structure of the Si:P δ-layer platform. In this work, we use high-resolution angle-resolved photoemission spectroscopy to reveal the structure of the electronic states which exist because of the high dopant density of the Si:P δ-layer. In contrast to published theoretical work, we resolve three distinct bands, the most occupied of which shows a large anisotropy and significant deviation from simple parabolic behaviour. We investigate the possible origins of this fine structure, and conclude that it is primarily a consequence of the dielectric constant being large (ca. double that of bulk Si). Incorporating this factor into tight-binding calculations leads to a major revision of band structure; specifically, the existence of a third band, the separation of the bands, and the departure from purely parabolic behaviour. This new understanding of the band structure has important implications for quantum proto-devices which are built on the Si:P δ-layer platform.

U2 - 10.1038/s41535-020-0237-1

DO - 10.1038/s41535-020-0237-1

M3 - Article

VL - 5

JO - npj Quantum Materials

JF - npj Quantum Materials

SN - 2397-4648

IS - 1

M1 - 34

ER -