Temperature-dependent broadening of coherent current peaks in InAs double quantum dots

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 20K 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. With increasing temperature, current peaks in biased double quantum dots broaden and acquire a background stemming from the impact of environmental degrees of freedom such as phonons. Here, the authors measure this effect in an InAs heterostructure and demonstrate that it can be captured theoretically by two bosonic baths that model charge and current fluctuations.