Phys.org July 14, 2022 Linear quantum measurements with independent particles are bounded by the standard quantum limit, which limits the precision achievable in estimating unknown phase parameters. The standard quantum limit can be overcome by entangling the particles, but the sensitivity is often limited by the final state readout, especially for complex entangled many-body states with non-Gaussian probability distributions. By implementing an effective time-reversal protocol in an optically engineered many-body spin Hamiltonian a team of researchers in the US (MIT, Harvard University) has demonstrated a quantum measurement with non-Gaussian states with performance beyond the limit of the readout scheme. This […]
Tag Archives: Signal amplification
A new amplifying technique for weak and noisy optical signals
Phys.org February 2, 2022 Mitigating the stochastic noise introduced during the generation, transmission, and detection of temporal optical waveforms remains a significant challenge across many applications. An international team of researchers (Canada, Spain) proposed a versatile concept for simultaneous amplification and noise mitigation of temporal waveforms, and successfully demonstrated on optical signals with bandwidths spanning several orders of magnitude, from the kHz to GHz scale. The concept was based on lossless temporal sampling of the incoming coherent waveform through Talbot processing. By reaching high gain factors (>100), they showed the recovery of ultra-weak optical signals, with power levels below the […]