On-chip generation and dynamic piezo-optomechanical rotation of single photons

Abstract

Integrated photonic circuits are key components for photonic quantum technologies and for the implementation of chip-based quantum devices. Future applications demand flexible architectures to overcome common limitations of many current devices, for instance the lack of tuneabilty or built-in quantum light sources. Here, we report on a dynamically reconfigurable integrated photonic circuit comprising integrated quantum dots (QDs), a Mach-Zehnder interferometer (MZI) and surface acoustic wave (SAW) transducers directly fabricated on a monolithic semiconductor platform. We demonstrate on-chip single photon generation by the QD and its sub-nanosecond dynamic on-chip control. Two independently applied SAWs piezo-optomechanically rotate the single photon in the MZI or spectrally modulate the QD emission wavelength. In the MZI, SAWs imprint a time-dependent optical phase and modulate the qubit rotation to the output superposition state. This enables dynamic single photon routing with frequencies exceeding one gigahertz. Finally, the combination of the dynamic single photon control and spectral tuning of the QD realizes wavelength multiplexing of the input photon state and demultiplexing it at the output. Our approach is scalable to multi-component integrated quantum photonic circuits and is compatible with hybrid photonic architectures and other key components for instance photonic resonators or on-chip detectors.

Dynamic Strain Modulation of a Nanowire Quantum Dot Compatible with a Thin-Film Lithium Niobate Photonic Platform

“…Coupling to superconducting qubits, , coherent electron transport between gate-defined QDs as well as coherent acoustic control of optically active QDs , have been demonstrated. In the latter case, the piezoelectric potential generated by the SAW can be used to transport photogenerated carriers to the QD, while the QD bandgap can also be modulated by the strain field of the SAW. − Among the various transferable emitters or defects, InAsP QDs embedded in an InP nanowire (NW) with a taper-shaped InP shell stands out as a good candidate. , Bright, high-purity, near transform-limited and indistinguishable single photons as well as entangled photons pairs , have been preferentially emitted along the long axis of the NW with a Gaussian transverse mode. This emission profile is advantageous for efficient coupling to single-mode waveguides and fibers.…”

Heterogeneous integration of superconducting thin films and epitaxial semiconductor heterostructures with lithium niobate

“…SAWs are highly appealing because of their universal coupling to dissimilar quantum systems [3,14]. SAW devices are fabricated in a planar manner using straightforward CMOS device processing techniques, which has enabled optomechanical transduction between solid-state quantum emitters [15][16][17], integrated photonic and phononic circuits [18][19][20][21], and many other demonstrations of SAW coupling to optically or electrically active quantum systems sensitive to strain or electric fields [22][23][24][25][26]. Another advantage of SAW devices is that they typically operate at gigahertz (GHz) frequencies, where they can be cooled to the phononic ground-state without active cooling protocols [14,17].…”

“…For single-channel timeresolved detection, the detection wavelength was scanned and the signal was recorded by a single photon avalanche diode (SPAD) with time resolution < 50 ps. The electrical pulses of the SPAD were recorded with time correlation electronics referenced to the electrical signal applied to the IDT[21,65].…”