Date and Time:  7-June-2023 15:00

Speaker:  Prof. Dr. Peter Michler, University of Stuttgart, Germany

Host: Zhiliang Yuan (BAQIS）

Title: Quantum Light Sources and a Quantum Memory for Quantum Photonic Networks

Abstract: 

Quantum photonic networks require sources of single, indistinguishable and entangled photon pairs with high brightness. Semiconductor quantum dots (QDs) hold great promise to meet these requirements. In many foreseen implementations of quantum photonic networks, photons must be able to propagate over long distances in silica fibers with limited absorption and wave packet dispersion. When propagating into silica fibers, photons in the so-called telecom C-band (1530 – 1565 nm) will experience the absolute minimum of absorption whereas in the O-band (1260 – 1360 nm) they can travel with vanishing dispersion together with limited absorption. A further requirement for a photonic quantum network is quantum memory in order to store and recall single-photon states on demand.

In this talk we report about recent highlights achieved with quantum dots emitting in the telecom O- and C-band [1-3]. This includes bright Purcell enhanced single-photon sources in the telecom O- and C-band based on quantum dots in circular Bragg gratings [2,3] and the study of resonance fluorescence of single In(Ga)As QDs emitting in the telecom C-band [4]. Moreover, we present the deterministic storage and retrieval of telecom quantum dots photons interfaced with an atomic quantum memory [5].

[1] S. L. Portalupi, M. Jetter and P. Michler, InAs quantum dots grown on metamorphic buffers as non-classical light sources at telecom C-band: a review, Semicond. Sci. Technol. 34, 053001 (2019)

[2] S. Kolatschek, et al., Bright Purcell enhanced single-photon source in the telecom O-band based on a quantum dot in a circular Bragg grating, Nano Lett. 21, 7740 (2021)

[3] C. Nawrath et al., High emission rate from a Purcell-enhanced triggered source of pure single photons in the telecom C-band, arXiv.2207.12898 (2022)

[4] C. Nawrath et al., Resonance fluorescence of single In(Ga)As quantum dots emitting in the telecom C-band, Appl. Phys. Lett. 118, 244002 (2021)

[5] S. E. Thomas et al., Deterministic storage and retrieval of telecom quantum dot photons interfaced with an atomic quantum memory, arXiv:230304166 (2023).

About the Speaker:

Peter Michler got his Physics Diploma and his PhD degree from the University of Stuttgart in 1990 and 1994, respectively. He worked as post-doc at the Max-Planck Institute for Solid State Research in Stuttgart from 1994 to 1995. From 1995 to 1999, he was a research group leader at the University of Bremen and from 1999 until 2000 he spent a one-year research stay at the University of California, Santa Barbara. In 2001, he performed his Habilitation at the University of Bremen and he became a professor in 2003 at the University of Stuttgart. Since May 2006, he is the head of the Institute for Semiconductor Optics and Functional Interfaces at the University of Stuttgart, concentrating research on quantum dots, quantum optics, semiconductor quantum light sources, photonic quantum technologies and semiconductor lasers.