Latest Quasiparticle Stories

Potential for optoelectronics, solar cells, valleytronics and more When the dry lubricant, molybdenum disulfide, is stripped down to a single layer of atoms, a tightly bound quasi-particle comprised of two electrons and a hole forms with unique spin and valley properties, researchers from Case Western Reserve University and colleagues discovered. These charged quasi-particles, called negative trions, can be manipulated to change the light absorbed and emitted from this two-dimensional...

If quantum computers are ever going to perform all those expected feats of code-breaking and number crunching, then their component qubits---tiny ephemeral quantum cells held in a superposition of internal states---will have to be protected from intervention by the outside world. In other words, decoherence, the loss of the qubits’ quantum integrity, has to be postponed. Now theoretical physicists at the Joint Quantum Institute (JQI) and the University of Maryland have done an important...

Direct Imaging by Berkeley Lab Researchers Confirms the Importance of Electron-Electron Interactions in Graphene Perhaps no other material is generating as much excitement in the electronics world as graphene, sheets of pure carbon just one atom thick through which electrons can race at nearly the speed of light – 100 times faster than they move through silicon. Superthin, superstrong, superflexible and superfast as an electrical conductor, graphene has been touted as a potential wonder...

With headlines proclaiming the discovery of the Higgs boson—the so-called God particle—particle physics has captured the imagination of the world, particularly among those who dwell on the nature of the cosmos. But this is only one puzzle seemingly solved in a universe of mysteries. In a recent paper in Physical Review Letters, Dartmouth physicists delve into another enigmatic particle. Majorana is a name whose very mention evokes a veil of mystery. On one level, it refers to a...

Ultracold quantum gases are an ideal experimental model system to simulate physical phenomena in condensed matter. In these gases, many-body states can be realized under highly controlled conditions and interactions between particles are highly tuneable. A research group led by Wittgenstein awardee Rudolf Grimm and START awardee Florian Schreck have now realized and comprehensively analyzed repulsive polarons for the first time. The scientists from the Institute of Quantum Optics and Quantum...

Findings support magnetic pairing theory that could lead to new improved superconductors By measuring how strongly electrons are bound together to form Cooper pairs in an iron-based superconductor, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, Cornell University, St. Andrews University, and collaborators provide direct evidence supporting theories in which magnetism holds the key to this material's ability to carry current with no resistance. Because...

Physicists show standard ‘quasiparticle’ theory breaks down at ‘quantum critical point’ A new study this week finds that “quantum critical points” in exotic electronic materials can act much like polarizing “hot button issues” in an election. Reporting in Nature, researchers from Rice University, two Max Planck Institutes in Dresden, Germany, and UCLA find that on either side of a quantum critical point, electrons fall into line and behave as traditionally expected, but at...

With the Advanced Light Source Berkeley Lab scientists explore the electronic structure of graphene in regions never before tested by experimentGraphene, a sheet of carbon only a single atom thick, was an object of theoretical speculation long before it was actually made. Theory predicts extraordinary properties for graphene, but testing the predictions against experimental results is often challenging.Now researchers using the Advanced Light Source (ALS) at the U.S. Department of Energy's...

Braided anyons could lead to more robust quantum computingWhen confined to a 2-dimensional sheet, some exotic particle-like structures known as anyons appear to entwine in ways that could lead to robust quantum computing schemes, according to research appearing in the November 1 issue of the journal Physical Review B. The physicists at Bell Laboratories who performed the research are hopeful the anyons can be induced to follow paths that twist into braids that would be much more resistant to...

Physicists are divided on whether string theory is a viable theory of everything, but many agree that it offers a new way to look at physical phenomena that have otherwise proven difficult to describe. In the past decade, physicists have used string theory to build a connection between quantum and gravitational mechanics, known as gauge/gravity duality.MIT physicists, led by Hong Liu and John McGreevy, have now used that connection to describe a specific physical phenomenon "” the behavior...