  Quantum systems as used for quantum computation or quantum sensing are
nowadays often realized in solid state devices as e.g. complex Josephson
circuits or coupled quantum-dot systems. Condensed matter as an environment
influences heavily the quantum coherence of such systems. Here, we investigate
electron transport through asymmetrically coupled InAs double quantum dots and
observe an extremely strong temperature dependence of the coherent current
peaks of single-electron tunneling. We analyze experimentally and theoretically
the broadening of such coherent current peaks up to temperatures of 20 K and we
are able to model it with quantum dissipation being due to two different
bosonic baths. These bosonic baths mainly originate from substrate phonons.
Application of a magnetic field helps us to identify the different quantum dot
states through their temperature dependence.
