Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spintronics approach enables new quantum technologies

05.06.2013
A team of researchers, including members of the University of Chicago’s Institute for Molecular Engineering, highlight the power of emerging quantum technologies in two recent papers published in the Proceedings of the National Academy of Sciences.
These technologies exploit quantum mechanics, the physics that dominates the atomic world, to perform disparate tasks such as nanoscale temperature measurement and processing quantum information with lasers.

The two papers are both based on the manipulation of the same material, an atomic-scale defect in diamond known as the nitrogen vacancy center. Both works also leverage the intrinsic “spin” of this defect for the applications in temperature measurement and information processing. This spintronics approach involves understanding and manipulating the spin of electronics for technological advancement.

“These studies build on research efforts undertaken over the last 20 years to isolate and control single electronic spins in the solid state,” said David Awschalom, a principle investigator on both papers and a Liew Family Professor in Molecular Engineering at UChicago. “Much of the initial motivation for working in this field was driven by the desire to make new computing technologies based on the principles of quantum physics. In recent years the research focus has broadened as we’ve come to appreciate that these same principles could enable a new generation of nanoscale sensors.”

Controlling qubits with light

In one PNAS paper posted April 22 and published in the May 7 print edition, Awschalom and six co-authors at the University of California, Santa Barbara and the University of Konstanz describe a technique that offers new routes toward the eventual creation of quantum computers, which would possess far more capability than modern classical computers.

In this application, Awschalom’s team has developed protocols to fully control the quantum state of the defect with light instead of electronics. The quantum state of interest in this defect is its electronic spin, which acts as quantum bit, or qubit, the basic unit of a quantum computer. In classical computers, bits of information exist in one of only two states: zero or one. In the quantum mechanical realm, objects can exist in multiple states at once, enabling more complex processing.

This all-optical scheme for controlling qubits in semiconductors “obviates the need to have microwave circuits or electronic networks,” Awschalom said. “Instead, everything can be done solely with photons, with light.”

As a fully optical method, it shows promise as a more scalable approach to qubit control. In addition, this scheme is more versatile than conventional methods and could be used to explore quantum systems in a broad range of materials that might otherwise be difficult to develop as quantum devices.

Single spin thermometers

The quantum thermometer application, reported in a PNAS contribution posted online May 6 and published in the May 21 print edition, represents a new direction for the manipulation of quantum states, which is more commonly linked to computing, communications, and encryption. In recent years, defect spins had also emerged as promising candidates for nanoscale sensing of magnetic and electric fields at room temperature. With thermometry now added to the list, Awschalom foresees the possibility of developing a multifunctional probe based on quantum physics.

“With the same sensor you could measure magnetic fields, electric fields and now temperature, all with the same probe in the same place at approximately the same time,” he said. “Perhaps most importantly, since the sensor is an atomic-scale defect that could be contained within nanometer-scale particles of diamond, you can imagine using this system as a thermometer in challenging environments such as living cells or microfluidic circuits.”

The key aspect of this innovation is the development of control techniques for manipulating the spin that make it a much more sensitive probe of temperature shifts. “We’ve been exploring the potential of defect spins for thermometry for the past few years,” said David Toyli, a graduate student in physics at UCSB and lead author of the temperature sensing work.

“This latest work is exciting because we’ve succeeded in adapting techniques used for stabilizing quantum information to measuring temperature-dependent changes in the quantum states. These techniques minimize the effects of environmental noise and allow us to make much more sensitive temperature measurements.”

The team of researchers, also including Slava Dobrovitski of the Department of Energy’s Ames Laboratory in Iowa, conducted experiments to determine the temperature range over which the spins could operate as a useful thermometer. It turns out that the particle spins can operate quite well at a wide temperature range, from room temperature to 500 degrees Kelvin (approximately 70 to 400 degrees Fahrenheit).

The chemical properties of a diamond-based thermometer also support the idea that this system could be useful for measuring temperature gradients in biological systems, such as the interior of living cells, Awschalom said. But the initial studies suggest the method is so flexible that it probably lends itself to uses yet to be imagined. “Like any new technology development, the exciting thing is what people will do with this now.”

Citations

“All-optical control of a solid-state spin using coherent dark states,” by Christopher G. Yale, Bob B. Buckley, David J. Christle, Guido Burkard, F. Joseph Heremans, Lee C. Bassett, and David D. Awschalom, Proceedings of the National Academy of Sciences, Vol. 110, No. 19, May 7, 2013, pages 7595-7600, originally published online April 22, 2013.

“Fluorescence thermometry enhanced by the quantum coherence of single spins in diamond,” by David M. Toyli, Charles F. de las Casas, David J. Christle, Viatcheslav V. Dobrovitski, and David D. Awschalom, Proceedings of the National Academy of Sciences, Vol. 110, No. 21, May 21, 2013, pages 8417-8421, originally published

Steve Koppes | EurekAlert!
Further information:
http://www.uchicago.edu
http://news.uchicago.edu/article/2013/06/04/spintronics-approach-enables-new-quantum-technologies

More articles from Physics and Astronomy:

nachricht Ultra-compact phase modulators based on graphene plasmons
27.06.2017 | ICFO-The Institute of Photonic Sciences

nachricht Smooth propagation of spin waves using gold
26.06.2017 | Toyohashi University of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>