[Seminar] Prof. Akira Oiwa / Photon-spin quantum interface using semiconductor spin qubits

Speaker

Prof. Akira Oiwa / The University of Osaka​
 

Title

Photon-spin quantum interface using semiconductor spin qubits

Abstract

Semiconductor spin qubits are well recognized as a promising platform for scalable fault-tolerant quantum computers (FTQCs) because of relatively long spin coherence time in solid state devices, high-electrical tuneability of the quantum states and applicability of industrial semiconductor large scale integration technologies [1]. In addition, semiconductors have great potential for applications in quantum communications because of their abilities for optical devices. Therefore, especially in quantum repeater applications, the semiconductor spin qubits provide a route to efficiently connect between spin qubit modules or quantum computers via optical fibers and construct quantum networks, contributing to realize secure quantum communications and distributed quantum computing [2].

In this talk, we present the quantum state conversion from single photon polarization
states to single electron spin states in gate-defined GaAs quantum dots (QDs) and its
experimental demonstration [3]. As recent significant achievements, we discuss the
enhancement of the conversion efficiency from a single photon to a single spin in a
quantum dot using photonic nanostructures [4]. Finally, we present a perspective of high conversion efficiency quantum repeaters operating directly at a telecom wavelength based on semiconductor spin qubits.

[1] G. Burkard et al., Rev. Mod. Phys. 95, 025003 (2023).
[2] A. Oiwa et al., J. Phys. Soc. Jpn. 86, 011008 (2017); L. Gaudreau et al., Semicond. Sci. Technol. 32, 093001 (2017).
[3] T. Fujita et al., Nature commun. 10, 2991 (2019); K. Kuroyama et al., Phys. Rev. B
10, 2991 (2019).
[4] R. Fukai et al., Appl. Phys. Express 14, 125001 (2021); S. Ji et al., Jpn. J. Appl. Phys. 62, SC1018 (2023).