Detecting an Itinerant Optical Photon Twice without Destroying It

Measuring a photonic qubit without destroying it.

Measuring the polarization of a single photon typically results in its destruction. We propose, demonstrate, and completely characterize a quantum nondemolition (QND) scheme for realizing such a measurement nondestructively. This scheme uses only linear optics and photodetection of ancillary modes to induce a strong nonlinearity at the single-photon level, nondeterministically. We vary this QND...

Comment on "measuring a photonic qubit without destroying it.

quantum nondemolition measurements Recently, Pryde et al. reported the demonstration of a quantum nondemolition (QND) scheme for single-photon polarization states with linear optics and projective measurements. In this experiment, a single photon with a specific polarization in the signal mode interacts on a beam splitter with a second polarized photon in the meter mode. A destructive polarizat...

An itinerant antiferromagnetic metal without magnetic constituents

The origin of magnetism in metals has been traditionally discussed in two diametrically opposite limits: itinerant and local moments. Surprisingly, there are very few known examples of materials that are close to the itinerant limit, and their properties are not universally understood. In the case of the two such examples discovered several decades ago, the itinerant ferromagnets ZrZn2 and Sc3I...

Checking it twice: an evaluation of checklists for detecting medication errors at the bedside using a chemotherapy model

OBJECTIVE To determine what components of a checklist contribute to effective detection of medication errors at the bedside. DESIGN High-fidelity simulation study of outpatient chemotherapy administration. SETTING Usability laboratory. PARTICIPANTS Nurses from an outpatient chemotherapy unit, who used two different checklists to identify four categories of medication administration errors...

Destroying Civilization, Destroying Nature