Regensburg 2022 – scientific programme

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QI: Fachverband Quanteninformation

QI 1: Implementations: Spin Qubits, Atoms, and Photons

QI 1.5: Talk

Monday, September 5, 2022, 10:45–11:00, H8

Cavity-mediated quantum gates between driven remote spin qubits — •Florian Kayatz, Jonas Mielke, and Guido Burkard — University of Konstanz, Konstanz D-78457, Germany

The implementation of two-qubit gates between distant qubits is of fundamental importance for quantum computing architectures involving many qubits. Considering cold ions confined in a linear trap, the Cirac-Zoller gate (CZ-gate) [1,2] constitutes such a two-qubit gate by exploiting the coupling of the ions through the collective quantized ion motion.

Here, we theoretically demonstrate a CZ-like gate between two spin qubits realized in gate defined semiconductor double quantum dots. In the envisioned system both spin qubits are coupled to a microwave resonator mode that has a similar function as the collective ion motion in the original CZ-gate. Recently, strong spin-photon coupling has been demonstrated [3] and, thus, allows for coherent population exchange between the spin qubit and the resonator mode. Thereby, two of the three main steps in the CZ-gate protocol can be realized. We describe in detail how the remaining step that requires the generation of a phase depending on the state of the second qubit and the resonator photon number can be implemented by driving the second DQD-system.

[1] Cirac, J. I. and Zoller, P., PRL 74, 4091 (1995)

[2] Schmidt-Kaler et al., Nature 422, 408-411 (2003)

[3] Mi et al., Nature 555, 7698 (2018)