We demonstrate a universal multi-mode linear optical quantum operation in the time domain using a scalable and programmable dual-loop-based optical circuit. This work holds great promise for time-multiplexed large-scale optical quantum information processing.
We demonstrate universal and programmable three-mode linear-optical operations in the time domain by realizing a scalable dual-loop optical circuit suitable for universal quantum information processing (QIP). The programmability, validity, and deterministic operation of our circuit are demonstrated by performing nine different three-mode operations on squeezed-state pulses, fully characterizing the outputs with variable measurements, and confirming their entanglement. Our circuit can be scaled up just by making the outer loop longer and also extended to universal quantum computers by incorporating feed forward systems. Thus, our work paves the way to large-scale universal optical QIP.
A quantum processor to import, process, and export optical quantum states is a common core technology enabling various photonic quantum information processing. However, there has been no photonic processor that is simultaneously universal, scalable, and programmable. Here, we report on an original loop-based single-mode versatile photonic quantum processor that is designed to be universal, scalable, and programmable. Our processor can perform arbitrarily many steps of programmable quantum operations on a given single-mode optical quantum state by time-domain processing in a dynamically controlled loop-based optical circuit. We use this processor to demonstrate programmable single-mode Gaussian gates and multistep squeezing gates. In addition, we prove that the processor can perform universal quantum operations by injecting appropriate ancillary states and also be straightforwardly extended to a multimode processor. These results show that our processor is programmable, scalable, and potentially universal, leading to be suitable for general-purpose applications.
Photonic quantum computing has been dramatically scaled up recently by the promising approach of combining the continuous-variable" and time-multiplexing" schemes. We report on our recent development of time-multiplexed programmable continuous-variable photonic quantum computing, including a programmable loop-based quantum processor for single-mode multi-step Gaussian gates and a programmable time-multiplexed squeezed light source for initial state preparation. Our works pave the way to large-scale programmable continuous-variable quantum computing.