This article is written in collaboration with V. Vyurkov and L. Fedichkin and is published in Physica E: Low-dimensional Systems and Nanostructures, 44, 501-505 (2011)
A charge-based qubit is subject to image forces originating in nearby metal gates. Displacement of charge in an oscillating qubit indispensably results in moving charges in metal. Therefore, Joule loss is one more source of qubit decoherence. We have estimated the quality of Rabi oscillations for a realistic double-quantum-dot as Q~100. This kind of decoherence cannot be suppressed by lowering temperature as it is evoked by surface roughness scattering of electrons which is almost insensitive to temperature. Possibilities to avoid such a decoherence are briefly discussed. The effect of energy dissipation and image charge potential on qubit dynamics is studied by means of a specific local-in-time non-Markovian master equation.