Researchers at Israel’s Bar-Ilan University, in collaboration with TII – the Quantum Research Center in Abu Dhabi, UAE, are leading a group project to advance quantum computing.
They are achieving this goal by improving the performance of the basic computational units of a superconducting quantum processor.
The improved qubit, called a “tunable superconducting flux qubit,” is a micron-sized superconducting loop where the electric current can flow clockwise, counterclockwise, or in a quantum superposition of both directions.
These characteristics would allow the computer to be much faster and more powerful than a normal computer. In order to “realize” the potential speed, the quantum computer must “operate” several hundred qubits simultaneously without them unintentionally interfering with each other.
As an alternative to what exists in quantum processors today, superconducting flux qubits have important advantages. First, they are very fast and reliable; second, it can be simpler to integrate many flux qubits into a processor compared to currently available technology.
“Imagine that you want to play a certain note on a piano, but you inadvertently play a number of keys simultaneously because the distance between the keys is not large enough. One of the main advantages of flux qubits is that the ‘pianist’ can still produce the sound he wants because of the large separation between the keys,” said Dr. Michael Stern, from the Department of Physics and the QUEST Center at Bar-Ilan University.
To stay with the piano analogy, the technological complication encountered by flux qubits until recently was the difficulty of controlling and changing their “tone.” It was virtually impossible to change the frequency of a flux qubit without destroying its coherence.
This research was conducted with funding from the Israel Science Foundation (ISF).