Home > Press > Scientists put the squeeze on electron spins
By squeezing the crystal in a controlled manner, and without applying magnetic fields, the researchers were able to watch the electron spins rotate (or precess) as they flow through the crystal.
Scientists put the squeeze on electron spins
Los Alamos, N.M. | June 16, 2005
University of California scientists working at Los Alamos National Laboratory have developed a novel method for controlling and measuring electron spins in semiconductor crystals of GaAs (gallium arsenide). The work suggests an alternative -- and perhaps even superior -- method of spin manipulation for future generations of "semiconductor spintronic" devices.
In research published in today's issue of the scientific journal Physical Review Letters, Scott Crooker and Darryl Smith describe their use of a scanning optical microscope to acquire two-dimensional images of spin-polarized electrons flowing in semiconductor crystals mounted on an optical cryostat while using a miniature "cryogenic vise" to apply gentle pressure. By squeezing the crystal in a controlled manner, and without applying magnetic fields, the researchers were able to watch the electron spins rotate (or precess) as they flow through the crystal.
According to Crooker, "electrons, in addition to their negative electronic charge, also possess a magnetic "spin". That is, each electron behaves like a little bar magnet, with north and south poles. Electron spins in semiconductors are typically manipulated by applying a magnetic field, but we've found we can do the same thing, in a controlled fashion, using the "vise". And, the resulting degree of spatial spin coherence is remarkably more robust compared to the spin precession induced by a magnetic field."
The cryogenic vise operates at only a few degrees above absolute zero (4 degrees Kelvin) and can be used to intentionally tip, rotate, and flip the electron spins. The research was conducted at the Pulsed Field Facility of the National High Magnetic Field Laboratory (NHMFL) at Los Alamos.
The research was funded by Los Alamos Laboratory-Directed Research and Development (LDRD) funding and the Defense Advanced Research Project Agency's SPins IN Semiconductors (SPINS) Program, which is designed to encourage research to exploit the spin degree of freedom of the electron and create revolutionary electronic devices with the potential to be very fast at very low power.
Alex H. Lacerda, Director of NHMFL-Los Alamos, states, "This work is an excellent example of how the LDRD program engenders strong inter-divisional relationships and enduring experimental-theoretical collaborations at Los Alamos for the pursuit of basic science."
The research fits into a broader area of expertise that Los Alamos National Laboratory maintains in the field of atomic physics in general, and spintronics research in particular.
About Los Alamos National Laboratory:
Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.
Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear deterrent, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to defense, energy, environment, infrastructure, health and national security concerns.
(505) 665-2085 (04-147)
Copyright © Los Alamos National Laboratory
If you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
The "Tipping Point" February 12th, 2014
UCF Researcher Bringing 3-D TV Back From The Dead February 12th, 2014
Diamond Defect Boosts Quantum Technology February 4th, 2014
Iran to Hold 2nd Prototype Nanotechnology Products Competition January 21st, 2014
Relativity shakes a magnet: Researchers from Mainz University demonstrate a new principle for magnetic recording / Publication in Nature Nanotechnology March 4th, 2014
Ion beams pave way to new kinds of valves for use in spintronics February 18th, 2014
Natural 3D Counterpart to Graphene Discovered: Researchers at Berkeley Labís Advanced Light Source Find New Form of Quantum Matter January 16th, 2014
A Deeper Look at Interfaces: Researchers at Berkeley Labís Advanced Light Source Develop New Technique for Probing Subsurface Electronic Structure January 15th, 2014
Malvern specialist to explore use of Nanoparticle Tracking Analysis for characterizing extracellular vesicles at ISEV 2014 March 11th, 2014
Thailand's Next Move on Research and Innovation March 11th, 2014
Arrowhead to Present at Barclays Global Healthcare Conference March 11th, 2014
Scientists build thinnest-possible LEDs to be stronger, more energy efficient March 10th, 2014