TY - JOUR
T1 - Enhanced current fluctuation in Coulomb blockade regime of multilevel quantum dot
AU - Iwasaki, Atsushi
AU - Eto, Mikio
N1 - Funding Information:
This work is partly supported by a Grant-in-Aid for Scientific Research (S) (No. 26220711) from Japan Society for the Promotion of Science and MEXT Grant-in-Aid for Scientific Research on Innovative Areas “Science of hybrid quantum systems” (No. 15H05870).
PY - 2017/8/15
Y1 - 2017/8/15
N2 - Nonequilibrium current fluctuation is theoretically studied through a multilevel quantum dot in the Coulomb blockade regime, where the higher-order tunneling processes, "cotunneling," are dominant in the transport. The current fluctuation shows a Poisson (super-Poisson) noise in the elastic (inelastic) cotunneling regime when the bias voltage eV between the leads is smaller (larger) than the excitation energy Δ from the ground level in the quantum dot. The super-Poisson noise is remarkably enhanced by the degeneracy of the excited states around the beginning of inelastic cotunneling at eV ≈ Δ, qualitatively in good agreement with a recent experimental result. An analytical expression is given for the current fluctuation as a function of degeneracy.
AB - Nonequilibrium current fluctuation is theoretically studied through a multilevel quantum dot in the Coulomb blockade regime, where the higher-order tunneling processes, "cotunneling," are dominant in the transport. The current fluctuation shows a Poisson (super-Poisson) noise in the elastic (inelastic) cotunneling regime when the bias voltage eV between the leads is smaller (larger) than the excitation energy Δ from the ground level in the quantum dot. The super-Poisson noise is remarkably enhanced by the degeneracy of the excited states around the beginning of inelastic cotunneling at eV ≈ Δ, qualitatively in good agreement with a recent experimental result. An analytical expression is given for the current fluctuation as a function of degeneracy.
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U2 - 10.1088/1742-6596/864/1/012034
DO - 10.1088/1742-6596/864/1/012034
M3 - Conference article
AN - SCOPUS:85028753808
SN - 1742-6588
VL - 864
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012034
T2 - 33rd International Conference on the Physics of Semiconductors, ICPS 2016
Y2 - 31 July 2016 through 5 August 2016
ER -