Featured Research

from universities, journals, and other organizations

Mechanical micro-drum used as quantum memory

Date:
March 13, 2013
Source:
National Institute of Standards and Technology (NIST)
Summary:
Researchers have demonstrated that information encoded as a specific point in a traveling microwave signal -- the vertical and horizontal positions of a wave pattern at a certain time -- can be transferred to the mechanical beat of a micro-drum and later retrieved with 65 percent efficiency.

Colorized image of NIST micro-drum and circuit on a sapphire backing. JILA researchers demonstrated that the drum might be used as a memory device in future quantum computers.
Credit: Teufel/NIST

One of the oldest forms of computer memory is back again -- but in a 21st century microscopic device designed by physicists at the National Institute of Standards and Technology (NIST) for possible use in a quantum computer.

The NIST team has demonstrated that information encoded as a specific point in a traveling microwave signal -- the vertical and horizontal positions of a wave pattern at a certain time -- can be transferred to the mechanical beat of a micro-drum and later retrieved with 65 percent efficiency, a good figure for experimental systems like this. The research is described in the March 14 issue of Nature. "We believe the mechanical drum motion could be used as a kind of local memory for quantum information systems," NIST physicist Konrad Lehnert says. "These experiments live at the boundary between classical and quantum systems."

The technique harks back to "delay line memory" that was used in some of the earliest electronic computers, including NIST's own 1950s computer, SEAC. Those devices were fairly simple. They temporarily stored values during computation in the form of acoustic waves traveling down a column of mercury or other fluid. By contrast, the NIST micro-drum memory would exploit a mechanical form of quantum physics.

NIST scientists introduced the micro-drum in 2011. The micro-drum is embedded in a resonant circuit and can beat at different frequencies. By applying microwaves at specific frequencies, researchers can achieve rapid, reliable exchanges between the circuit's electrical energy, in the form of microwave photons (light particles), and the drum's mechanical energy in the form of phonons (units of vibration).

An applied microwave tone can cool the drum down to its lowest-energy ground state, with less than one quantum of energy -- the quantum regime, where the drum can store and convert quantum information. The same interaction transfers information from microwaves in the circuit to the drum, while converting the drum to a temporary state beating at the received frequencies. A key innovation in the latest experiments is the ability to rapidly switch the circuit-drum interactions on and off based on the intensity of the applied microwave tone.

The drum has certain practical advantages as a quantum storage device. Its size and fabrication method are compatible with the devices used for chip-based superconducting quantum bits (qubits), which might be used to represent information in quantum computers. The drum also can retain quantum information for about the same length of time as superconducting circuits can. Quantum computers would rely on the rules of quantum mechanics, nature's rules for the submicroscopic world, to potentially solve important problems that are intractable using today's technology.

In the latest experiments, the quantum information is stored in the amplitude (vertical position) and phase (horizontal position) of the microwave pulse, or waveform, similar to the way some cellular telephones work, Lehnert says. Although this is a classical approach, the experiments are quasi-quantum because the fluctuations, or "noise," in the measurements are quantum mechanical, Lehnert says.

In 8,000 tries, the research team was able to prepare, transfer, store and recapture information 65 percent of the time. This is a good level of efficiency given the early stage of global research on quantum memories; competing quantum memory devices include special crystals and, in nonsolid systems, atomic gases. In the future, researchers plan to combine qubits with the micro-drum, which could serve as either a quantum memory or as an interface between otherwise incompatible systems such as those operating at microwave and optical frequencies. The advance may benefit fundamental physics experiments, quantum information systems and precise force sensing.

The experiments were performed at JILA, a joint institute of NIST and the University of Colorado Boulder, and co-authors include physicists from NIST's Boulder campus. The research was supported by the Defense Advanced Research Projects Agency, the National Science Foundation and NIST.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. T. A. Palomaki, J. W. Harlow, J. D. Teufel, R. W. Simmonds, K. W. Lehnert. Coherent state transfer between itinerant microwave fields and a mechanical oscillator. Nature, 2013; 495 (7440): 210 DOI: 10.1038/nature11915

Cite This Page:

National Institute of Standards and Technology (NIST). "Mechanical micro-drum used as quantum memory." ScienceDaily. ScienceDaily, 13 March 2013. <www.sciencedaily.com/releases/2013/03/130313142528.htm>.
National Institute of Standards and Technology (NIST). (2013, March 13). Mechanical micro-drum used as quantum memory. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2013/03/130313142528.htm
National Institute of Standards and Technology (NIST). "Mechanical micro-drum used as quantum memory." ScienceDaily. www.sciencedaily.com/releases/2013/03/130313142528.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins