Abstract
We have demonstrated 42% squeezing of 4.2-K thermal noise using a Josephson-parametric amplifier operated at 19.4 GHz. The amplifier has been operated at 0.1 K with an excess noise of 0.28 K referred to the input port. This is less than the vacuum fluctuation noise h/2k=0.47 K at 19.4 GHz. The amplifier thus is less noise than a linear phase-insensitive amplifier such as a maser could in principle be.
| Original language | English |
|---|---|
| Pages (from-to) | 764-767 |
| Number of pages | 4 |
| Journal | Physical Review Letters |
| Volume | 60 |
| Issue number | 9 |
| DOIs | |
| State | Published - 1988 |