TY - JOUR
T1 - Excitation spectroscopy of few-electron states in artificial diatomic molecules
AU - Hatano, T.
AU - Tokura, Y.
AU - Amaha, S.
AU - Kubo, T.
AU - Teraoka, S.
AU - Tarucha, S.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/6/27
Y1 - 2013/6/27
N2 - We study the excitation spectroscopy of few-electron parallel coupled double quantum dots (DQDs). By applying a finite source drain voltage to a DQD, the first excited states observed in nonequilibrium charging diagrams can be classified into two kinds in terms of the total effective electron number in the DQD, assuming a core filling. When there are an odd (even) number of electrons, a one- (two-) electron antibonding (triplet) state is observed as the first excited state. On the other hand, at a larger source drain voltage, we observe higher excited states where additional single-particle excited levels are involved. Eventually, we identify the excited states with a calculation using the Hubbard model and, in particular, we elucidate the quadruplet state, which is normally forbidden by the spin blockade caused by the selection rule.
AB - We study the excitation spectroscopy of few-electron parallel coupled double quantum dots (DQDs). By applying a finite source drain voltage to a DQD, the first excited states observed in nonequilibrium charging diagrams can be classified into two kinds in terms of the total effective electron number in the DQD, assuming a core filling. When there are an odd (even) number of electrons, a one- (two-) electron antibonding (triplet) state is observed as the first excited state. On the other hand, at a larger source drain voltage, we observe higher excited states where additional single-particle excited levels are involved. Eventually, we identify the excited states with a calculation using the Hubbard model and, in particular, we elucidate the quadruplet state, which is normally forbidden by the spin blockade caused by the selection rule.
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U2 - 10.1103/PhysRevB.87.241414
DO - 10.1103/PhysRevB.87.241414
M3 - Article
AN - SCOPUS:84879937471
VL - 87
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 24
M1 - 241414
ER -