Rice physicists move 1 step closer to quantum computer

Rice University physicists have created a tiny “electron superhighway” that could one day be useful for building a quantum computer, a new type of computer that will use quantum particles in place of the digital transistors found in today's microchips.

In a recent paper in Physical Review Letters, Rice physicists Rui-Rui Du and Ivan Knez describe a new method for making a tiny device called a “quantum spin Hall topological insulator.” The device, which acts as an electron superhighway, is one of the building blocks needed to create quantum particles that store and manipulate data.

Today's computers use binary bits of data that are either ones or zeros. Quantum computers would use quantum bits, or “qubits,” which can be both ones and zeros at the same time, thanks to the quirks of quantum mechanics.

This quirk gives quantum computers a huge edge in performing particular types of calculations, said Du, professor of physics and astronomy at Rice. For example, intense computing tasks like code-breaking, climate modeling and biomedical simulation could be completed thousands of times faster with quantum computers.

“In principle, we don't need many qubits to create a powerful computer,” he said. “In terms of information density, a silicon microprocessor with 1 billion transistors would be roughly equal to a quantum processor with 30 qubits.”

In the race to build quantum computers, researchers are taking a number of approaches to creating qubits. Regardless of the approach, a common problem is making certain that information encoded into qubits isn't lost over time due to quantum fluctuations. This is known as “fault tolerance.”

The approach Du and Knez are following is called “topological quantum computing.” Topological designs are expected to be more fault-tolerant than other types of quantum computers because each qubit in a topological quantum computer will be made from a pair of quantum particles that have a virtually immutable shared identity. The catch to the topological approach is that physicists have yet to create or observe one of these stable pairs of particles, which are called “Majorana fermions” (pronounced MAH-yor-ah-na FUR-mee-ons).

The elusive Majorana fermions were first proposed in 1937, although the race to create them in a chip has just begun. In particular, physicists believe the particles can be made by marrying a two-dimensional topological insulator — like the one created by Du and Knez — to a superconductor.

Topological insulators are oddities; although electricity cannot flow through them, it can flow around their narrow outer edges. If a small square of a topological insulator is attached to a superconductor, Knez said, the elusive Majorana fermions are expected to appear precisely where the materials meet. If this proves true, the devices could potentially be used to generate qubits for quantum computing, he said.

Knez spent more than a year refining the techniques to create Rice's topological insulator. The device is made from a commercial-grade semiconductor that's commonly used in making night-vision goggles. Du said it is the first 2-D topological insulator made from a material that physicists already know how to attach to a superconductor.

“We are well-positioned for the next step,” Du said. “Meanwhile, only experiments can tell whether we can find Majorana fermions and whether they are good candidates for creating stable qubits.”

The research was funded by the National Science Foundation, Rice University, the Hackerman Advanced Research Program, the Welch Foundation and the Keck Foundation.

A copy of the PRL paper is available at: http://prl.aps.org/abstract/PRL/v107/i13/e136603

Media Contact

Jade Boyd EurekAlert!

More Information:

http://www.rice.edu

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors