Biomedical subjects

K L Pregnell

Publications and source records attributed to K L Pregnell.

2 recordsLinked to original sources

PubMed2006

Measuring nonlinear functionals of quantum harmonic oscillator states.

Using only linear interactions and a local parity measurement we show how entanglement can be detected between two harmonic oscillators. The scheme generalizes to measure both linear and nonlinear functionals of an arbitrary oscillator state. This leads to many applications including purity tests, eigenvalue estimation, entropy, and distance measures--all without the need for nonlinear interactions or complete state reconstruction. Remarkably, experimental realization of the proposed scheme is already within the reach of current technology with linear optics.

Journal Article↗

PubMed2002

Single-shot measurement of quantum optical phase.

Although the canonical phase of light, which is defined as the complement of photon number, has been described theoretically by a variety of distinct approaches, there have been no methods proposed for its measurement. Indeed doubts have been expressed about whether or not it is measurable. Here we show how it is possible, at least in principle, to perform a single-shot measurement of the canonical phase using beam splitters, mirrors, phase shifters, and photodetectors.

Journal Article↗