Cancellation of Internal Quantum Noise of an Amplifier by Quantum Correlation
Abstract
Quantum noise is usually added in an amplification process through the internal degrees of the amplifier. Coupling the squeezed state to the internal degree can suppress the extra noise. Here, we demonstrate another method: when the internal degree of the amplifier is correlated with the input signal via quantum entanglement, quantum destructive interference between the input and the internal degree may result in noise reduction at the amplified output. We achieve a quantum noise reduction of 2.3 dB at the output and an improvement of 4.0±0.2dB in signal-to-noise ratio during the amplification process with a quantum noise gain of 4.5 dB.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2013
- DOI:
- Bibcode:
- 2013PhRvL.111c3608K
- Keywords:
-
- 42.50.-p;
- 42.50.Dv;
- 42.50.Lc;
- 42.65.Yj;
- Quantum optics;
- Nonclassical states of the electromagnetic field including entangled photon states;
- quantum state engineering and measurements;
- Quantum fluctuations quantum noise and quantum jumps;
- Optical parametric oscillators and amplifiers