A shield made of sound
Physicists at Harvard have found that a steady stream of sound waves can shield a fragile quantum bit from its noisy surroundings. In experiments, the technique nearly tripled how long the qubit held information. The results were published in Nature Physics.
Quantum bits, or qubits, are the building blocks of quantum computers. They are easily disturbed by heat, vibration, and electrical noise. Any disturbance can destroy the information they hold. Keeping qubits stable for longer is one of the biggest challenges in the field.
How the shield works
The Harvard team worked with a silicon-vacancy spin in diamond, a common type of qubit. They sent a steady stream of sound waves toward the qubit. The waves created a protective barrier that blocked out the noisy environment.
The result was a sharp jump in coherence time, the length of time a qubit can hold information. The team said the effect was consistent across many repeated tests, which suggests the method is reliable rather than accidental.
What comes next
The findings open a path toward sound-based quantum networks on chips. Sound waves travel slowly, which makes them useful for connecting qubits that sit close together. The approach could also support hybrid quantum systems that combine many different types of qubits.
Researchers caution that the work is still early. The shield works in a lab setting, and scaling it to full quantum computers will take time. But the team says the method is simple to apply and could be combined with existing error-correction techniques to build more reliable machines.