Double-dot charge qubit and transport via dissipative cotunneling.
We investigate transport through an exotic charge qubit composed of two strongly capacitively coupled quantum dots, each being independently connected to a side gate which in general exhibits a fluctuating electrostatic field (i.e., Johnson-Nyquist noise). Two quantum phases are found: the "Kondo" phase where an orbital-Kondo entanglement emerges and a "local moment" phase in which the noise destroys the Kondo effect leaving the orbital spin unscreened and resulting in a clear suppression of the conductance. In the Kondo realm, the transfer of charge across the setting is accompanied by zero-point charge fluctuations in the two dissipative environments and then the I-V characteristics are governed by what we call "dissipative cotunneling."
Li
Mei-Rong
MR
Département de Physique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1.
Le Hur
Karyn
K