A single-photon switch and transistor enabled by a solid-state quantum memory

Abstract

Single-photon switches and transistors generate strong photon-photon interactions that are essential for quantum circuits and networks. However, the deterministic control of an optical signal with a single photon requires strong interactions with a quantum memory, which has been challenging to achieve in a solid-state platform. We demonstrate a single-photon switch and transistor enabled by a solid-state quantum memory. Our device consists of a semiconductor spin qubit strongly coupled to a nanophotonic cavity. The spin qubit enables a single 63-picosecond gate photon to switch a signal field containing up to an average of 27.7 photons before the internal state of the device resets. Our results show that semiconductor nanophotonic devices can produce strong and controlled photon-photon interactions that could enable high-bandwidth photonic quantum information processing.

Nano‐Cavity QED with Tunable Nano‐Tip Interaction

“…Furthermore, room temperature strong coupling could enable the development of chip‐based and broadly distributable platforms for technologies based on quantum transduction and quantum‐state control . Extension of nano‐cQED to the single photon limit would further enable quantum elements such as single‐photon switching, control of single photons by emitter states and single emitters by photons, and single‐photon optical transistors . Additionally, coherent control of the quantum state of an emitter through time domain Rabi flopping is required for preparation and read‐out of quantum states but has not yet been achieved using plasmonic nano‐cavities.…”

Ultra‐Long Lifetimes of Single Quantum Emitters in Monolayer WSe2/hBN Heterostructures

“…For example, in the context of quantum memory applications, long‐lifetime emitters could serve as a way to preserve the polarization state of a photonic qubit for later use. More recently, the usefulness of long‐lifetime single emitters has been demonstrated in the form of single‐photon switching of a transistor enabled by a solid‐state quantum memory …”

A Spin–Photon Interface Using Charge-Tunable Quantum Dots Strongly Coupled to a Cavity

“…[11][12][13] These applications require the spin-state of the quantum dot to modulate the cavity reflectivity, allowing the spin to control the state of the reflected photons (e.g., polarization and frequency).Several studies have demonstrated such strong spin-photon interfaces between the electron spin of a charged quantum dot and cavity, 14-17 enabling optical nonlinearities such as Kerr rotations 16,17 and single-photon transistors. 15 These studies have relied on probabilistically charged quantum…”