Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer
graphene (BLG) are a promising quantum information platform because of
their long spin decoherence times, high sample quality, and tunability.
Importantly, the shape of QD states determines the electron energy
spectrum, the interactions between electrons, and the coupling of
electrons to their environment, all of which are relevant for quantum
information processing. Despite its importance, the shape of BLG QD
states remains experimentally unexamined. Here we report direct
visualization of BLG QD states by using a scanning tunneling microscope.
Strikingly, we find these states exhibit a robust broken rotational
symmetry. By using a numerical tight-binding model, we determine that
the observed broken rotational symmetry can be attributed to low energy
anisotropic bands. We then compare confined holes and electrons and
demonstrate the influence of BLG's nontrivial band topology. Our study
distinguishes BLG QDs from prior QD platforms with trivial band
topology.
%0 Journal Article
%1 WOS:000599507100039
%A Ge, Zhehao
%A Joucken, Frederic
%A Quezada, Eberth
%A da Costa, Diego R
%A Davenport, John
%A Giraldo, Brian
%A Taniguchi, Takashi
%A Watanabe, Kenji
%A Kobayashi, Nobuhiko P
%A Low, Tony
%A Jr., Jairo Velasco
%C 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
%D 2020
%I AMER CHEMICAL SOC
%J NANO LETTERS
%K Berry bilayer curvature; dots; graphene; information; microscopy} quantum scanning tunneling {quantum
%N 12
%P 8682-8688
%R 10.1021/acs.nanolett.0c03453
%T Visualization and Manipulation of Bilayer Graphene Quantum Dots with
Broken Rotational Symmetry and Nontrivial Topology
%V 20
%X Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer
graphene (BLG) are a promising quantum information platform because of
their long spin decoherence times, high sample quality, and tunability.
Importantly, the shape of QD states determines the electron energy
spectrum, the interactions between electrons, and the coupling of
electrons to their environment, all of which are relevant for quantum
information processing. Despite its importance, the shape of BLG QD
states remains experimentally unexamined. Here we report direct
visualization of BLG QD states by using a scanning tunneling microscope.
Strikingly, we find these states exhibit a robust broken rotational
symmetry. By using a numerical tight-binding model, we determine that
the observed broken rotational symmetry can be attributed to low energy
anisotropic bands. We then compare confined holes and electrons and
demonstrate the influence of BLG's nontrivial band topology. Our study
distinguishes BLG QDs from prior QD platforms with trivial band
topology.
@article{WOS:000599507100039,
abstract = {Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer
graphene (BLG) are a promising quantum information platform because of
their long spin decoherence times, high sample quality, and tunability.
Importantly, the shape of QD states determines the electron energy
spectrum, the interactions between electrons, and the coupling of
electrons to their environment, all of which are relevant for quantum
information processing. Despite its importance, the shape of BLG QD
states remains experimentally unexamined. Here we report direct
visualization of BLG QD states by using a scanning tunneling microscope.
Strikingly, we find these states exhibit a robust broken rotational
symmetry. By using a numerical tight-binding model, we determine that
the observed broken rotational symmetry can be attributed to low energy
anisotropic bands. We then compare confined holes and electrons and
demonstrate the influence of BLG's nontrivial band topology. Our study
distinguishes BLG QDs from prior QD platforms with trivial band
topology.},
added-at = {2022-05-23T20:00:14.000+0200},
address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
author = {Ge, Zhehao and Joucken, Frederic and Quezada, Eberth and da Costa, Diego R and Davenport, John and Giraldo, Brian and Taniguchi, Takashi and Watanabe, Kenji and Kobayashi, Nobuhiko P and Low, Tony and Jr., Jairo Velasco},
biburl = {https://www.bibsonomy.org/bibtex/2b9f30495ebce40c337c92287863ddb03/ppgfis_ufc_br},
doi = {10.1021/acs.nanolett.0c03453},
interhash = {0c9add1c73e627275999eb2d822e153c},
intrahash = {b9f30495ebce40c337c92287863ddb03},
issn = {1530-6984},
journal = {NANO LETTERS},
keywords = {Berry bilayer curvature; dots; graphene; information; microscopy} quantum scanning tunneling {quantum},
number = 12,
pages = {8682-8688},
publisher = {AMER CHEMICAL SOC},
pubstate = {published},
timestamp = {2022-05-23T20:00:14.000+0200},
title = {Visualization and Manipulation of Bilayer Graphene Quantum Dots with
Broken Rotational Symmetry and Nontrivial Topology},
tppubtype = {article},
volume = 20,
year = 2020
}