”Quantum entanglement”, a phrase first coined by Erwin Schr¨ odinger1, describes a condition of the separated parts of the same quantum system in which each of the parts can only be described by referencing the state of other part. This is one of the most counterintuitive aspects of quantum mechanics, because classically one would expect system parts out of speed-of-light contact to be completely independent. Thus, entanglement represents a kind of quantum connectedness in which measurements on one isolated part of (...) an entangled quantum system have non-classical consequences for the outcome of measurements performed on the other (possibly very distant) part of the same system. This quantum connectedness that enforces the measurement correlation and state-matching in entangled quantum systems has come to be called quantum nonlocality. (shrink)

The most time consuming effort has been toward building a precision, servo-controlled rotary drive to turn the attractor. After discovering our Nanomotion HR1 Ultra-High-Vacuum motor was incapable of continuous operation in a vacuum environment (due to heat management issues), we were forced to redesign the system such that the motor remained in atmosphere. We are pleased with the final performance. Fig. 2.1-1A..

The question we have been investigating is whether the nonlocality of standard quantum mechanics is the private domain of Nature, as is generally assumed by the physics community, or whether in special circumstances the nonlocal connection between subsystems can be used to send signals from one observer to another. With the aid of generous private contributions and some use of CENPA resources, we have continued the work on this test of nonlocal quantum communication, which has been reported in the past (...) three years1�2�3. The initial configuration of the experiment, as described in the first two references, employed a high power argon-ion laser operating at about 1 W in the ultraviolet at 351 nm that pumped nonlinear crystals (BBO or LiIO3) to produce pairs of momentum-entangled 702 nm photons, on which measurements were subsequently performed. It was concluded that signal-to-noise limitations from fluoresence photons competing with the down-converted photons prevented the planned measurements using the initial configuration. (shrink)