Electronic current in a nano-mechanical kicked electron shuttle

Role of coherence in quantum-dot-based nanomachines within the Coulomb blockade regime

“…10,[12][13][14][15][16][17][18][19][20][21][22][23][24] In recent years, the reverse process in which heat or charge currents are used to propel a mechanical device has also gained considerable attention. [25][26][27][28][29][30][31][32][33][34][35][36][37] In all the above systems, it is assumed that the typical size of the device is smaller than the characteristic coherence length of electrons. It is clear then that quantum mechanics becomes crucial for the description of these forms of nanodevices, which can be put together under the generic name of quantum machines.…”

“…In this case, some form of rate equation relating the occupation probabilities of the quantum-dot states is typically used to describe the system, while the coherence between them can be disregarded in a first approximation. Quantum pumping, 10,15,[22][23][24]29,[42][43][44][45] shuttle transport, 37,46 and even adiabatic quantum motors 31 have been studied by using this approach. Other strategies, like the nonequilibrium Green's function formalism, have also been used in the past to study quantum pumping within the Coulomb blockade regime.…”