A revolutionary way to store information as sound waves

Quantum computing, just like traditional computing, requires a way to store and process the information it uses. In the computer you’re using now, information should be stored – whether it’s pictures of your dog, reminders of a friend’s birthday, or words you type in your browser’s address bar. somewhere. Quantum computing, a relatively new field, is still exploring where and how quantum information is stored.

An innovative way to store quantitative information

In a paper recently published in the journal nature physicsMohammad Mir Hosseini, assistant professor of electrical engineering and applied physics at Caltech, demonstrates a new method his lab developed for efficiently translating electrical quantum states into sound and vice versa. This type of translation may allow the storage of quantum information prepared by future quantum computers, which are likely to be made from electrical circuits.

Mohammad Mir Hosseini and his team presented an innovative way to store quantum information by translating electrical quantum states into sound. The new technique uses phonons and avoids the energy loss associated with previous methods. It allows longer storage times and represents a major advance in quantum computing. Credit: Moian Clarification

This method uses what are known as phonons, which are the acoustic equivalent of a particle of light called a Photon. (Remember that in quantum mechanics, all waves are particles and vice versa.) The experiment is looking for phonons to store quantum information because it’s relatively easy to build small devices that can store these mechanical waves.

The use of sound waves to store information

To understand how a sound wave can store information, imagine a very resonant chamber. Now, suppose you need to remember your grocery list for the afternoon, so you open the door to that room and yell, “Eggs, bacon, and milk!” And shut the door. An hour later, when it’s time to go to the grocery store, you open the door, bang your head inside, and hear your voice still repeating, “Eggs, bacon, and milk!” You just used sound waves to store information.

Muhammad Mir Hosseini. Credit: California Institute of Technology

Of course, in the real world, an echo like this wouldn’t last long, and your voice might end up so distorted that you can no longer form your own words, not to mention using an entire room to store a bit of data would be ridiculous. The research team’s solution is a small device consisting of flexible plates that vibrate with sound waves at extremely high frequencies. When an electrical charge is placed on those plates, they become able to interact with electrical signals that carry quantum information. This allows this information to be streamed into the device for storage, and taken out for later use – unlike the room door you were screaming at earlier in this story.

Previous research and new developments

According to Mohammad Mir Hosseini, previous studies have investigated a special type of material known as piezoelectric as a means of converting mechanical energy into electrical energy in quantum applications.

“These materials tend, however, to cause energy losses to electric and sound waves, and loss is a big killer in the quantum realm,” Mirhosseini says. In contrast, the new method developed by Mir Hosseini and his team is independent of the properties of specific materials, which makes it compatible with certified quantum devices, which are based on microwaves.

Conclusion: developments and challenges

Creating efficient storage devices with small footprints has been another practical challenge for researchers working in quantum applications, says Alchem ​​Bozkurt, a graduate student in Mirhoseni’s group and lead author of the paper.

“However, our method enables the storage of quantum information from electrical circuits for periods up to two orders of magnitude longer than other compact mechanical devices,” he adds.

Reference: “Quantum Electromechanical Interface for Long-Life Phonons” By Alchem ​​Bozkurt, Han Zhao, Chaitaly Joshi, Henri G. Leduc, Peter K. Day, and Mohamed Mirhseni, June 22, 2023, Available Here. nature physics.
DOI: 10.1038/s41567-023-02080-w

Co-authors are Chaitali Joshi and Han Zhao, both postdoctoral researchers in electrical engineering and applied physics. and Peter Day and Henri Leduc, scientists at the Jet Propulsion Laboratory, which is operated by the California Institute of Technology. NASA. The research was funded in part by the KNI-Wheatley Scholars Program.