Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice physicists discover ultrasensitive microwave detector

09.12.2010
Researchers use magnets to tune supercooled gallium arsenide semiconductors

Physicists from Rice University and Princeton University have discovered how to use one of the information technology industry's mainstay materials -- gallium arsenide semiconductors -- as an ultrasensitive microwave detector that could be suitable for next-generation computers. The discovery comes at a time when computer chip engineers are racing both to add nanophotonic devices directly to microchips and to boost processor speeds beyond 10 gigahertz (GHz).

"Tunable photon-detection technology in the microwave range is not well-developed," said Rice physicist Rui-Rui Du, the study's lead author. "Single-photon detectors based on superconductors in the 10-GHz to 100-GHz range are available, but their resonance frequency has been difficult to tune. Our findings suggest that tunable single-photon detection may be within reach with ultrapure gallium arsenide."

The study, which is available online and due to appear in print this week in Physical Review Letters, is the latest result from a long-term collaboration between Du and Princeton University physicist Loren Pfeiffer, whose group produces the world's purest samples of gallium arsenide. For the new study, Rice graduate student Yanhua Dai cooled one of Pfeiffer's ultrapure samples to below 4 degrees Kelvin -- the temperature of liquid helium. She then bombarded the sample with microwaves while applying a weak magnetic field -- approximately the same strength as that of a refrigerator magnet. Du and Dai were surprised to find that microwaves of a specific wavelength resonated strongly with the cooled sample. They also found they could use the magnet to tune this resonance to specific microwave frequencies.

Du said previous experiments have typically measured weak resonance effects from microwaves. "A signal level of 1 percent is a common measurement. In our case, the change was a thousand times that much."

While the team does not yet understand the mechanism that leads to such a sensitive reaction, they are eagerly pursuing follow-up research to try to prove they can use the effect for single-photon measurements.

A photon is the smallest possible unit of light or electromagnetic radiation. By incorporating devices that create, transmit and measure digital information via photons, rather than with electrons, makers of computer chips hope to produce computers that are both faster and more powerful.

"The clock speed of a new computer right now is about 2 GHz," Du said. "For the next generation, the industry is shooting for around 100 GHz, which is a microwave device. The phenomenon we've observed is in this region, so we hope it may be useful for them."

Additional co-authors include Princeton scientist Ken West. The research was supported by the National Science Foundation.

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Physics and Astronomy:

nachricht A better way to weigh millions of solitary stars
15.12.2017 | Vanderbilt University

nachricht A chip for environmental and health monitoring
15.12.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>