Expected to hit a barrier in a decade, Moore's Law may have reached its limit pushing for new physics discoveries for making significantly faster computers. A team of physicists at Rice University have created an "electron superhighway" -- a machine that would utilize quantum particles instead of the digital transistors in today's microchips that could one day be useful for building a Quantum Computer.

The device is a semiconductor chip which contains hundreds of tiny "electron superhighways," submicroscopic devices -- one of the building blocks necessary to create quantum particles that can store and manipulate data.

Rui-Rui Du, a professor of physics and astronomy, and graduate student Ivan Knez describe the new method for making the device, known as "quantum spin Hall topological insulator," in a paper published in Physical Review Letters, journal of the American Physical Society.

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

While the advances at Rice University may bring us closer to a day when we might use quantum computing, there is still plenty of work to do and plenty of breakthroughs to accomplish. The struggle now is to make qubits more reliable, as information becomes lost over time due to quantum fluctuations, a phenomenon 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).

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.

“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.”