Spin-coherent dot-cavity electronics

Clemens Rössler, David Oehri, Oded Zilberberg, Gianni Blatter, Matija Karalic, Jana Pijnenburg, Andrea Hofmann, Thomas Ihn, Klaus Ensslin, Christian Reichl, Werner Wegscheider

Department of Physics, ETH Zurich, Switzerland

Quantum engineering requires controllable artificial systems with quantum coherence exceeding the device size and operation time. This can be achieved with geometrically confined low-dimensional electronic structures embedded within ultraclean materials, with prominent examples being artificial atoms (quantum dots) and quantum corrals (electronic cavities). Combining the two structures, we implement a mesoscopic coupled dot-cavity system in a high-mobility two-dimensional electron gas, and obtain an extended spin-singlet state in the regime of strong dot-cavity coupling. Engineering such extended quantum states presents a viable route for nonlocal spin coupling that is applicable for quantum information processing.