Optoelectronics/Quantum Devices

Heterogenous quantum systems for single photon delay and pulse shaping

Photonic quantum technology is an exciting field in science and technology. Possible applications include secure quantum communication, photonic quantum computers and, in the long term, the quantum internet. These have in common that information is encoded in single photons that act as flying qubits. Importantly, these flying qubits need to be efficiently connected with stationary
qubits to realize quantum memories and quantum gates. The overall goal of this project is to develop and test a quantum memory for storage and readout, as well as for efficient spectral/temporal waveform manipulation of single quantum dot photons.

In our project, a heterogeneous quantum interface between semiconductor quantum dots and a quantum memory implemented in alkaline atoms is realized for the first time. This key building block of quantum nanophotonics
enables the generation of almost perfectly indistinguishable photons with high entanglement fidelity in quantum repeater protocols. At the same time, we plan that quantum information can be encoded into the temporal envelope and phase of individual photons, enabling a
quantum information transfer with high capacity and large alphabet. The underlying technological approach is to combine efficient and on-demand photon generation in semiconductor quantum dots with quantum memories, which are implemented in warm atomic vapor. The source is deterministically realized by in-situ electron beam lithography of single quantum dot circular Bragg grating devices.

Quick Info

Project startNovember 2020
Funding sourceDeutsche Forschungsgemeinschaft (DFG)
Funding IDRE 2974/28-1