All-optical measurement-device-free feedforward enabling ultra-fast quantum information processing

TL;DR

This paper demonstrates an all-optical, measurement-device-free feedforward system achieving a 1.3 THz clock rate for quantum information processing, surpassing electronic limitations and paving the way for ultra-fast optical quantum computers.

Contribution

The authors introduce a novel all-optical feedforward method using PPLN waveguides, enabling quantum operations at THz speeds without electronic measurement devices.

Findings

Achieved a 1.3 THz feedforward clock rate.

Demonstrated deterministic quantum information processing at ultra-fast speeds.

Eliminated electronic measurement bottlenecks in optical QIP.

Abstract

Optical circuit systems, unlike other systems, have the potential to perform quantum information processing (QIP) at higher clock rate than conventional processing. The approach utilizing the electromagnetic field of light allows deterministic QIP by feedforward process, which counteracts the quantum randomness by performing adaptive quantum operation according to the measurement result of an entangled state. However, conventional feedforward with electronic measurement devices has limited the clock rate of the QIP down to around 100 MHz. In this paper, we demonstrate a variable squeezing gate with a clock rate of 1.3 THz by all-optical measurement-device-free feedforward. We utilize a periodically poled lithium niobate (PPLN) waveguide as an optical parametric amplifier, which eliminates the need for electronic measuring devices and enables ultra-fast feedforward. Experimental results demonstrate that our all-optical QIP operates at a THz clock rate, representing a major step toward a true optical quantum computer which opens the curtain to a new era of ultra-fast information processing.