Researchers Create Super-thin Silica Fibers for Quantum Computers

Researchers have found a way of making a critical component of future quantum computers.

According to researchers at the Joint Quantum Institute at the University of Maryland, ultra-high transmission optical nanofibers can be made using a fine thread of silica fiber.

The process of making the optical nanofiber includes attaching the two ends of the strand to two small motors. Then letting an unflickering flame melt the silica thread until the middle part of the thread becomes soft and then pull it apart. The process, researchers say, will help make a silica strand that is about 200 times thinner than a human hair.

The flame source used in the fabrication process is a mixture of hydrogen and oxygen in two-to-one ratio. The ratio ensures that water vapour is the only by-product of the process.

The team has been working on optics-based atom traps. The new study describes a more efficient way of making these traps.

Quantum computers                                                         

Quantum Computing promises faster, efficient computers that can run several calculations simultaneously. Current computers use 0 and 1 to store data, while quantum computers rely on qubits or quantum bits. These qubits can exist as 0, 1 or an in-between (superposition) state at once.

Qubits tend to lose their superposition states quickly - a phenomenon called decoherence. The current study tries to solve this problem in quantum computing.

Researchers proposed that one can use a hybrid quantum processor; trapped atoms can serve as the memory and superconducting qubits can be the processor. Atoms can hold the superposition state for a long time and semi-conducting qubits can quickly perform the calculations.

"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, according to a news release.

There was a problem with this approach though. According to Hoffman, most atomic traps need superconductors and high optical power or magnetic fields. But, superconductors don't like high optical power.

This is why the silica nanofiber is needed. These fibers create optics-based, low-power atom traps that "get along" with superconductors.

These ultra thin wires are just 530 nanometers in diameter, which is less than the wavelength of light used to trap atoms. Some amount of the light escapes the fiber as an evanescent wave. Researchers said that this evanescent wave can be used to trap atoms a few hundred nanometers from the surface of the fiber.

The study is published in the journal AIP Advances.