The sub-band structure of atomically sharp dopant profiles in silicon
(2020) In npj Quantum Materials 5(1).- Abstract
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... (More)
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.
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- author
- Mazzola, Federico ; Chen, Chin Yi ; Rahman, Rajib ; Zhu, Xie Gang ; Polley, Craig M. LU ; Balasubramanian, Thiagarajan LU ; King, Phil D.C. ; Hofmann, Philip ; Miwa, Jill A. and Wells, Justin W. LU
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- in
- npj Quantum Materials
- volume
- 5
- issue
- 1
- article number
- 34
- publisher
- Nature Publishing Group
- external identifiers
-
- scopus:85085901598
- ISSN
- 2397-4648
- DOI
- 10.1038/s41535-020-0237-1
- language
- English
- LU publication?
- yes
- id
- b123bd42-a22b-4fbc-bbba-6015b5ac0d44
- date added to LUP
- 2020-06-29 08:57:12
- date last changed
- 2022-04-18 23:10:00
@article{b123bd42-a22b-4fbc-bbba-6015b5ac0d44,
abstract = {{<p>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.</p>}},
author = {{Mazzola, Federico and Chen, Chin Yi and Rahman, Rajib and Zhu, Xie Gang and Polley, Craig M. and Balasubramanian, Thiagarajan and King, Phil D.C. and Hofmann, Philip and Miwa, Jill A. and Wells, Justin W.}},
issn = {{2397-4648}},
language = {{eng}},
number = {{1}},
publisher = {{Nature Publishing Group}},
series = {{npj Quantum Materials}},
title = {{The sub-band structure of atomically sharp dopant profiles in silicon}},
url = {{http://dx.doi.org/10.1038/s41535-020-0237-1}},
doi = {{10.1038/s41535-020-0237-1}},
volume = {{5}},
year = {{2020}},
}