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Physics Frontier Center News

Given enough time, a forgotten cup of coffee will lose its appeal and cool to room temperature. One way of telling this tepid tale involves a stupendous number of coffee molecules colliding like billiard balls with themselves and colder molecules in the air above. Those constant collisions siphon energy away from the coffee, bit by bit, in a process that physicists call thermalization.

But this story doesn’t mention quantum physics, and scientists think that thermalization must...

Alan Migdall and Elohim Becerra and their colleagues at the Joint Quantum Institute have devised an optical detection scheme with an error rate 25 times lower than the fundamental limit of the best conventional detector. They did this by employing not passive detection of incoming light pulses. Instead the light is split up and measured numerous times.

boson spin-hall thumb

Every electrical device is enabled by the movement of charge, or current. ‘Spintronics’ taps into a different electronic attribute, an intrinsic quantum property known as spin, and may yield devices that operate on the basis of spin-transport. JQI/CMTC theorists have been developing a model for what happens when spins are trapped in an optical lattice structure with a “double-valley” feature....

Interfering Waves

A new extreme for sub-wavelength interference has been achieved by JQI scientists using thermal light and small-photon-number light detection. Achieving this kind of sharp interference pattern could be valuable for performing a variety of high-precision physics and astronomy measurements.

JQI scientists have added an important technique to the atomtronics arsenal, a method for analyzing a superfluid circuit component called a ‘weak link’. The result, detailed in the online journal Physical Review X, is the first direct measurement of the current-phase relationship of a weak link in a cold atom system.

JQI researchers led by Mohammad Hafezi report detailed measurements of the transmission (how much energy is lost) and delay for edge-state light and for bulk-route light on a photonic chip.

Recently physicists led JQI Fellow Christopher Monroe have executed an MRI-like diagnostic on a crystal of interacting quantum spins. They predict that their method is scalable and may be useful for validating experiments with much larger ensembles of interacting spins.

In quantum mechanics, interactions between particles can give rise to entanglement, which is a strange type of connection that could never be described by a non-quantum, classical theory. These connections, called quantum correlations, are present in entangled systems even if the objects are not physically linked (with wires, for example). Entanglement is...

Michael Lewis’s bestselling book Flash Boys describes how some brokers, engaging in high frequency trading, exploit fast telecommunications to gain fraction-of-a-second advantage in the buying and selling of stocks. But you don’t need to have billions of dollars riding on this-second securities transactions to appreciate the importance of fast signal processing. From internet to video...

Papers from the groups of Ian Spielman and Jake Taylor were recently chosen as "Highlights of 2013" by the New Journal of Physics. The articles are listed below To see more highlights, visit http://iopscience.iop.org/1367-2630/page/highlights-of-2013

From CMNS at UMD

Three University of Maryland students have been awarded scholarships by the Barry M. Goldwater Scholarship and Excellence in Education Foundation, which encourages students to pursue advanced study and careers in the sciences, engineering and mathematics. A fourth student received honorable mention.

UMD juniors Geoffrey Ji, Michael Mandler and...

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Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...

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