Research News

 A new experiment conducted at the University of California at Berkeley used quantum information techniques for a precision test of a cornerstone principle of physics, namely Lorentz invariance.  This precept holds that the results of a physics experiment do not depend on its absolute spatial orientation.  The work uses quantum-correlated electrons within a pair of calcium ions to look for shifts in quantum energy levels with unprecedented sensitivity.   JQI Adjunct Fellow and University of Delaware professor Marianna Safronova, who contributed a theoretical analysis of the data, said that

Quantum computers will someday perform calculations impossible for conventional digital computers.  But for that to happen, the core quantum information must be preserved against contamination from the environment.  In other words, decoherence of qubits must be forestalled.  Coherence, the ability of a system to retain quantum integrity---meaning that one part of the system can be used to predict the behavior of other parts---is an important consideration.

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. This new result opens up a novel path for generating what’s known as the spin Hall effect, an important example of spin-transport.