Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultra-thin wires for quantum computing

17.06.2014

Carefully fabricating nanofibers by heating and pulling may make for highly-efficient, optics-based, low-power atom traps

Take a fine strand of silica fiber, attach it at each end to a slow-turning motor, gently torture it over an unflickering flame until it just about reaches its melting point and then pull it apart. The middle will thin out like a piece of taffy until it is less than half a micron across -- about 200 times thinner than a human hair.


This image depicts light propagating through an optical nanofiber during the pulling process with a SEM image of the 536 nanometer diameter waist.

Credit: J. E. Hoffman and E. Edwards / JQI at UMD

That, according to researchers at the Joint Quantum Institute at the University of Maryland, is how you fabricate ultrahigh transmission optical nanofibers, a potential component for future quantum information devices, which they describe in AIP Publishing's journal AIP Advances.

Quantum computers promise enormous power, but are notoriously tricky to build. To encode information in qubits, the fundamental units of a quantum computer, the bits must be held in a precarious position called a superposition of states. In this fragile condition the bits exist in all of their possible configurations at the same time, meaning they can perform multiple parallel calculations.

The tendency of qubits to lose their superposition state too quickly, a phenomenon known as decoherence, is a major obstacle to the further development of quantum computers and any device dependent on superpositions. To address this challenge, researchers at the Joint Quantum Institute proposed a hybrid quantum processor that uses trapped atoms as the memory and superconducting qubits as the processor, as atoms demonstrate relatively long superposition survival times and superconducting qubits perform operations quickly.

"The idea is that we can get the best of both worlds," said Jonathan Hoffman, a graduate student in the Joint Quantum Institute who works in the lab of principal investigators Steven Rolston and Luis Orozco. However, a problem is that superconductors don't like high optical power or magnetic fields and most atomic traps use both, Hoffman said.

This is where the optical nanofibers come in: The Joint Quantum Institute team realized that nanofibers could create optics-based, low-power atom traps that would "play nice" with superconductors. Because the diameter of the fibers is so minute -- 530 nanometers, less than the wavelength of light used to trap atoms -- some of the light leaks outside of the fiber as a so-called evanescent wave, which can be used to trap atoms a few hundred nanometers from the fiber surface.

Hoffman and his colleagues have worked on optical nanofiber atom traps for the past few years. Their AIP Advances paper describes a new procedure they developed that maximizes the efficiency of the traps through careful and precise fabrication methods.

The group's procedure, which yields an improvement of two orders of magnitude less transmission loss than previous work, focuses on intensive preparation and cleaning of the pre-pulling environment the nanofibers are created in.

In the fabrication process, the fiber is brushed through the flame to prevent the formation of air currents, which can cause inconsistencies in diameter to arise, as it is pulled apart and tapered down. The flame source is a mixture of hydrogen and oxygen gas in a precise two-to-one ratio, to ensure that water vapor is the only byproduct. The motors are controlled by an algorithm based on the existing work of a group in Vienna, which calculates the trajectories of the motors to produce a fiber of the desired length and profile.

Previous pulling methods, such as carbon dioxide lasing and chemical etching, were limited by the laser's insufficient diameter and by a lesser degree of control over tapering length, respectively.

Future work includes interfacing the trapped atoms with the superconducting circuits held at 10 mKelvin in a dilution refrigerator, as well as guiding more complicated optical field patterns through the fiber (higher-order modes) and using these to trap atoms.

###

The article, "Ultrahigh transmission optical nanofibers," is authored by J.E. Hoffman, S. Ravets, J.A. Grover, P. Solano, P.R. Kordell, J.D. Wong-Campos, L.A. Orozco and S.L. Rolston. It will be published in AIP Advances on June 17, 2014 (DOI: . After that date, it may be accessed at: http://scitation.aip.org/content/aip/journal/adva/4/6/10.1063/1.4879799

ABOUT THE JOURNAL

AIP Advances is a fully open access, online-only, community-led journal. It covers all areas of applied physical science. With its advanced web 2.0 functionality, the journal puts relevant content and discussion tools in the hands of the community to shape the direction of the physical sciences. See: http://aipadvances.aip.org

Jason Socrates Bardi | Eurek Alert!
Further information:
http://www.aip.org

Further reports about: AIP Quantum diameter fiber nanofibers nanometers quantum computers superconductors

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>