Real-time analog circuit for auto-correlative weak-value amplification in the time domain

TL;DR

This paper presents a real-time analog circuit for auto-correlative weak-value amplification (AWVA), enhancing quantum parameter estimation accuracy and noise robustness compared to standard methods, with potential applications in various detection schemes.

Contribution

The authors developed and tested a real-time analog circuit for AWVA, demonstrating improved sensitivity and noise resistance over SWVA in quantum parameter estimation.

Findings

AWVA circuit achieves higher accuracy than SWVA.

The circuit maintains sensitivity for frequencies 200 Hz to 20 kHz.

AWVA shows robustness against noise at low SNRs.

Abstract

The auto-correlative weak-value amplification (AWVA) technique demonstrates distinct advantages over standard weak-value amplification (SWVA) for quantum parameter estimation. To achieve enhanced precision in real-time parameter estimation, the AWVA requires additional resources compared to SWVA, namely real-time multiplication and integrator modules. We implemented a real-time analog circuit for AWVA using an AD835 multiplier and an NE5532 operational amplifier for the integrator. The circuit was tested using Gaussian pointers in the AWVA scheme, exhibiting sufficient sensitivity for Gaussian pointers with frequencies 200 Hz < f < 20kHz. Compared to SWVA, AWVA achieves higher accuracy and superior robustness against noise at signal-to-noise ratios (SNRs) of -12 dB < SNR < -4 dB. Beyond quantum metrology, the circuit is applicable to diverse detection schemes for correlated signals.