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Surprising Control over Photoelectrons from a Topological Insulator

By Guest PostMarch 24, 2013Science3d topological insulators, alessandra lanzara, als, angle resolved, arpes, atoms, berkeley lab, chris jozwiak, data collection, dirac point, dung hai lee, electronic states, energy momentum diagrams, field of spintronics, flight analyzer, german, graphene, incident light, laser beam, magnetic surface, momentum space, p polarized, photoelectrons, photoemission spectroscopy, quantum computing, s polarization, s polarized, senkrecht, spin polarized, spin time, steve louie, strange crystalline materials, tis, topological insulator, university of california, zahid hussain

Berkeley Lab scientists discover how a photon beam can flip the spin polarization of electrons emitted from an exciting new material

Plain-looking but inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. Even at room temperature, a single chunk of TI is a good insulator in the bulk, yet behaves like a metal on its surface.

Researchers find TIs exciting partly because the electrons that flow swiftly across their surfaces are “spin polarized”: the electron’s spin is locked to its momentum, perpendicular to the direction of travel. These interesting electronic states promise many uses – some exotic, like observing never-before-seen fundamental particles, but many practical, including building more versatile and efficient high-tech gadgets, or, further into the future, platforms for quantum computing. (more…)

Long Predicted Atomic Collapse State Observed in Graphene

By Guest PostMarch 19, 2013Sciencealex zettl, andrey shytov, artificial atomic nuclei, atomic collapse behavior, atomic collapse state, berkeley lab, calcium dimers, dillon wong, electrical conductor, electronic devices, electronic resonance, electrons, energy, graphene, holy grail, michael crommie, nuclear physics, nucleus, predictions, quantum mechanical phenomenon, relativistic quantum mechanics, roland kawakami, scanning tunneling microscope, smoking gun, Space, stable circular orbits, stm, stm spectroscopy, ultra high vacuum, ultrafast transistors, william regan, yang wang

Berkeley Lab researchers recreate elusive phenomenon with artificial nuclei

The first experimental observation of a quantum mechanical phenomenon that was predicted nearly 70 years ago holds important implications for the future of graphene-based electronic devices. Working with microscopic artificial atomic nuclei fabricated on graphene, a collaboration of researchers led by scientists with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have imaged the “atomic collapse” states theorized to occur around super-large atomic nuclei.

“Atomic collapse is one of the holy grails of graphene research, as well as a holy grail of atomic and nuclear physics,” says Michael Crommie, a physicist who holds joint appointments with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Physics Department. “While this work represents a very nice confirmation of basic relativistic quantum mechanics predictions made many decades ago, it is also highly relevant for future nanoscale devices where electrical charge is concentrated into very small areas.” (more…)

IBM Scientists First to Distinguish Individual Molecular Bonds

By Guest PostSeptember 14, 2012Scienceafm, alejandro criado, atom diameter, atomic force, bandwidth wireless, bond, buckyball, c60, carbon carbon, carbon monoxide, chemical bond, chemical structure, ciqus, co, diego pena, diodes, enrique guitian, graphene, hexagon, ibm, individual molecule, leo gross, light emitting, microscopy, noncontact, oleds, organic, pahs, pentagon, polyaromatic systems, polycyclic aromatic hydrocarbons, scientist, technique

Atomic force microscopy helps scientists to reveal the bond order and length of bonds within molecules

Technique can be used to study future devices made from graphene

Zurich, Switzerland – 14 Sep 2012: IBM scientists have been able to differentiate the chemical bonds in individual molecules for the first time using a technique known as noncontact atomic force microscopy (AFM).

The results push the exploration of using molecules and atoms at the smallest scale and could be important for studying graphene devices, which are currently being explored by both industry and academia for applications including high-bandwidth wireless communication and electronic displays. (more…)

A Direct Look at Graphene

By Guest PostAugust 5, 2012Sciencegraphene, graphene sheets, honeycomb lattice, pure carbon, relativistic fermions

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. (more…)

Tag Archives: graphene

Surprising Control over Photoelectrons from a Topological Insulator

Long Predicted Atomic Collapse State Observed in Graphene

IBM Scientists First to Distinguish Individual Molecular Bonds

A Direct Look at Graphene