Double-dot charge qubit and transport via dissipative cotunneling

We investigate electron cotunneling through an exotic charge qubit composed of two strongly capacitively coupled quantum dots (QDs), each being independently connected to a side gate which in general exhibits a fluctuating electrostatic field ({\em 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 cotunneling differs from the usual cotunneling through a single dot due to the peculiar phase space for particle-hole excitations; The transfer of charge across the setting is also accompanied by zero-point charge fluctuations in the two dissipative environments and the I-V characteristics are governed by what we call dissipative cotunneling.