Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST develops 'dimmer switch' for superconducting quantum computing

30.04.2010
Scientists at the National Institute of Standards and Technology (NIST) have developed the first "dimmer switch" for a superconducting circuit linking a quantum bit (qubit) and a quantum bus—promising technologies for storing and transporting information in future quantum computers.

The NIST switch is a new type of control device that can "tune" interactions between these components and potentially could speed up the development of a practical quantum computer.

Quantum computers, if they can be built, would use the curious rules of quantum mechanics to solve certain problems that are now intractable, such as breaking today's most widely used data encryption codes, or running simulations of quantum systems that could unlock the secrets of high-temperature superconductors. Unlike many competing systems that store and transport information using the quantum properties of individual atoms, superconducting qubits use a "super flow" of oscillating electrical current to store information in the form of microwave energy. Superconducting quantum devices are fabricated like today's silicon processor chips and may be easy to manufacture at the large scales needed for computation.

As described in a forthcoming paper in Physical Review Letters,* the new NIST switch can reliably tune the interaction strength or rate between the two types of circuits—a qubit and a bus—from 100 megahertz to nearly zero. The advance could enable researchers to flexibly control the interactions between many circuit elements in an intricate network as would be needed in a quantum computer of a practical size.

Other research groups have demonstrated switches for two or three superconducting qubits coupled together, but the NIST switch is the first to produce predictable quantum behavior over time with the controllable exchange of an individual microwave photon (particle of light) between a qubit and a resonant cavity. The resonant cavity serves as what engineers call a "bus"—a channel for moving information from one section of the computer to another. "We have three different elements all working together, coherently (in concert with each other) and without losing a lot of energy," says the CU-Boulder graduate student Michael (Shane) Allman who performed the experiments with NIST physicist Ray Simmonds, the principal investigator.

All three components (qubit, switch, and cavity) were made of aluminum in an overlapping pattern on a sapphire chip (see image). The switch is a radio-frequency SQUID (superconducting quantum interference device), a magnetic field sensor that acts like a tunable transformer. The circuit is created with a voltage pulse that places one unit of energy—a single microwave photon—in the qubit. By tuning a magnetic field applied to the SQUID, scientists can alter the coupling energy or transfer rate of the single photon between the qubit and cavity. The researchers watch this photon slosh back and forth at a rate they can now adjust with a knob.

The switch research was supported in part by the Army Research Office. Simmonds's group previously demonstrated the first superconducting quantum bus between qubits (see "Digital Cable Goes Quantum: NIST Debuts Superconducting Quantum Computing Cable," www.nist.gov/public_affairs/releases/quantum_cable.html, which also describes how the superconducting qubits operate).

* M.S. Allman, F. Altomare, J.D. Whittaker, K. Cicak, D. Li, A. Sirois, J. Strong, J.D. Teufel, R.W. Simmonds. 2010. rf-SQUID-Mediated Coherent Tunable Coupling Between a Superconducting Phase Qubit and a Lumped Element Resonator. Physical Review Letters. Forthcoming.

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov
http://www.nist.gov/public_affairs/releases/quantum_cable.html

More articles from Physics and Astronomy:

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

nachricht Physicists discover mechanism behind granular capillary effect
24.05.2017 | University of Cologne

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: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>