Researchers at the University of Maryland, College Park have developed the world's first reprogrammable quantum computer. This breakthrough device is small and can only solve simple algorithms for now, but it opens the door wider to larger quantum computers in the future.

The milestone brings scientists closer to the elusive goal of building fully functioning quantum computers that can instantly perform lightning fast calculations far outstripping today's digital computers.

Like Us on Facebook

University of Maryland researchers built the computer using just five qubits that replaced the standard bits in digital computers. Each qubit is an ion, or an electrically charged particle, trapped in a magnetic field.

The scientists can use lasers to manipulate these five ytterbium atoms, infusing them with precise amounts of energy and influencing their interactions with each other. By doing this, the researchers can program and reprogram the quantum computer with a variety of algorithms.

"Until now, there hasn't been any quantum-computing platform that had the capability to program new algorithms into their system. They're usually each tailored to attack a particular algorithm," said study lead author Shantanu Debnath, a quantum physicist and optical engineer at the University of Maryland.

The researchers tested their device on three algorithms quantum computers could execute quickly.

One, the "Deutsch-Jozsa algorithm," is typically used only for tests of quantum-computing capabilities. Another, the "Bernstein-Vazirani algorithm," can also be used to probe for errors in quantum computing. The last, the quantum Fourier transform algorithm, is an element in quantum-computing encryption-breaking applications.

Researchers successfully ran the Deutsch-Jozsa and Bernstein-Vazirani algorithms 95 and 90 percent of the time, respectively. The quantum Fourier transform algorithm had a 70 percent success rate.This algorithm is among the most complicated quantum calculations. Researchers will test more algorithms on their device, said Debnath.

"We'd like this system to serve as a test bed for examining the challenges of multiqubit operations, and find ways to make them better."

The scientists detailed their findings in the Aug. 4 issue of the journal Nature.

Tagsreprogrammable quantum computer, University of Maryland, College Park, quantum computers, Shantanu Debnath