Quantum state transfer of hole spin qubits in quantum dots

Hole spins in semiconductor quantum dots (QDs) are attracting significant attention as candidates for fast, highly coherent, spin qubits [1-4]. They have long coherence time due to the weak hyperfine coupling to nuclear spins and rapid operation times due to the inherently strong spin-orbit coupling (SOC).

This work investigates how to control a two-hole spin qubit consisting of a singlet-triplet hole state. For that purpose, we implement a driving protocol based on Shortcuts to Adiabaticity (STA), minimizing noise effects while enhancing robustness [5, 6]. We analyze its feasibility to manipulate hole spin qubits and compare it with other alternative protocols. We can initialize the qubit in an arbitrary state and perform a NOT gate by changing the detuning between dots. In addition, we achieve a SWAP-like two-qubit gate with fidelity beyond the error correction threshold [7]. Finally, we study the long-range transfer of hole spin states across a linear quantum dot array. These protocols will be designed by STA schemes, being able to speed up the transference while maintaining or even increasing the fidelity and robustness against charge noise.

References

[1] D. Jirovec, et al, Nat. Mat. 20, 1106-1112 (2021)

[2] N. W. Hendrickx et al., Nat. Commun. 11, 3478 (2020)

[3] A. Bogan, et al., PRL 118, 167701 (2017)

[4] A. Bogan, et al., PRL 120, 207701 (2018)

[5] Y. Ban, et al., Nanotech. 29, 505201 (2018)

[6] Y. Ban, et al., Adv. Quantum Technol. 2, 1900048 (2018)

[7] D. Fernández-Fernández, et al., arXiv 2204.07453 (2022)