Magnetic-Field Dependence of Tunnel Couplings in Carbon Nanotube Quantum Dots

TY - JOUR

T1 - Magnetic-Field Dependence of Tunnel Couplings in Carbon Nanotube Quantum Dots

AU - Grove-Rasmussen, Kasper

AU - Grap, S.

AU - Paaske, Jens

AU - Flensberg, Karsten

AU - Andergassen, Sabine

AU - Meden, Volker

AU - Jørgensen, Henrik Ingerslev

AU - Muraki, K.

AU - Fujisawa, T.

PY - 2012/4/26

Y1 - 2012/4/26

N2 - By means of sequential and cotunneling spectroscopy, we study the tunnel couplings between metallic leads and individual levels in a carbon nanotube quantum dot. The levels are ordered in shells consisting of two doublets with strong- and weak-tunnel couplings, leading to gate-dependent level renormalization. By comparison to a one- and two-shell model, this is shown to be a consequence of disorder-induced valley mixing in the nanotube. Moreover, a parallel magnetic field is shown to reduce this mixing and thus suppress the effects of tunnel renormalization.

AB - By means of sequential and cotunneling spectroscopy, we study the tunnel couplings between metallic leads and individual levels in a carbon nanotube quantum dot. The levels are ordered in shells consisting of two doublets with strong- and weak-tunnel couplings, leading to gate-dependent level renormalization. By comparison to a one- and two-shell model, this is shown to be a consequence of disorder-induced valley mixing in the nanotube. Moreover, a parallel magnetic field is shown to reduce this mixing and thus suppress the effects of tunnel renormalization.

U2 - 10.1103/PhysRevLett.108.176802

DO - 10.1103/PhysRevLett.108.176802

M3 - Journal article

SN - 0031-9007

VL - 108

SP - 176802

JO - Physical Review Letters

JF - Physical Review Letters

IS - 17

ER -