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arXiv · 2308.05455

Protocols to measure the non-Abelian Berry phase by pumping a spin qubit through a quantum-dot loop

Baksa Kolok·András Pályi
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Abstract

A quantum system constrained to a degenerate energy eigenspace can undergo a nontrival time evolution upon adiabatic driving, described by a non-Abelian Berry phase. This type of dynamics may provide logical gates in quantum computing that are robust against timing errors. A strong candidate to realize such holonomic quantum gates is an electron or hole spin qubit trapped in a spin-orbit-coupled semiconductor, whose twofold Kramers degeneracy is protected by time-reversal symmetry. Here, we propose and quantitatively analyze protocols to measure the non-Abelian Berry phase by pumping a spin qubit through a loop of quantum dots. One of these protocols allows to characterize the local internal Zeeman field directions in the dots of the loop. We expect a near-term realisation of these protocols, as all key elements have been already demonstrated in spin-qubit experiments. These experiments would be important to assess the potential of holonomic quantum gates for spin-based quantum information processing.

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Baksa Kolok, András Pályi. 2023-08-10. Protocols to measure the non-Abelian Berry phase by pumping a spin qubit through a quantum-dot loop. https://doi.org/10.1103/physrevb.109.045438

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