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Updated: May 28, 2025

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
Switching Spin Filling Sequence in a Bilayer Graphene Quantum Dot through Trigonal Warping
Guo-Quan Qin1,2,3, Fang-Ming Jing1,2,3, Tian-Yue Hao1,3
1University of Science and Technology of China, CAS Key Laboratory of Quantum Information, Hefei, Anhui 230026, China.
Abstract:
We demonstrate a switchable electron shell structure in a bilayer graphene quantum dot by manipulating the trigonal warping effect upon electrical gating. Under a small perpendicular electric field, the lowest s shell is sequentially filled with two spin-up and two spin-down electrons of opposite valleys. When increasing the electric field, an additional threefold minivalley degeneracy is generated so that the s shell can be filled with 12 electrons with the first (last) six electrons having the same spin polarization. The switched spin filling sequence demonstrates the possibility of using the trigonal warping effect to electrically access and manipulate the spin degree of freedom in bilayer graphene.
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