New Technology Uses Sound Waves to Monitor and Control Quantum States

Acoustic resonators found in devices like smartphones and Wi-Fi systems are known to degrade over time. However, monitoring this degradation has been a challenge for scientists. Now, researchers from Harvard SEAS and Purdue University have developed a groundbreaking method using atomic vacancies in silicon carbide to measure the stability of these resonators. They have also demonstrated the ability to manipulate quantum states, opening up new possibilities for accelerometers, gyroscopes, clocks, and quantum networking.

Acoustic resonators play a vital role in our daily lives. Most smartphones and Wi-Fi systems use these resonators as filters to eliminate unwanted noise and enhance signal quality. While acoustic resonators are more stable than their electrical counterparts, they still degrade over time. Currently, there is no efficient way to actively monitor and analyze the degradation of these widely-used devices.

The research team, led by Evelyn Hu from the Harvard John A. Paulson School of Engineering and Applied Sciences, has found a solution using atomic vacancies in silicon carbide. By leveraging these vacancies, they can both measure the stability and quality of acoustic resonators and control quantum states.

Silicon carbide is a commonly used material for microelectromechanical systems (MEMS) and has excellent performance for quality factor. However, crystal growth defects and manufacturing defects can cause stress-concentration regions inside the resonator, leading to degradation.

Traditionally, X-rays have been the only way to observe the internal dynamics of acoustic resonators. However, this method is expensive and can only be done in specialized laboratories. The new technique developed by the research team allows for non-destructive monitoring of the acoustic energy inside the resonator, providing insights into its performance and potential areas of degradation.

Furthermore, the research team discovered that the defects in silicon carbide can also be used as qubits in a quantum system. By mechanically deforming the material with acoustic waves, they can control the coherence of spin, achieving a level of control similar to magnetic fields. This finding opens up new avenues for quantum technologies that rely on spin coherence.

The research was published in Nature Electronics, and the team believes that their method could revolutionize the monitoring and control of acoustic resonators while also advancing quantum information processing.


How do acoustic resonators work?

Acoustic resonators are devices used to filter out noise and enhance the quality of signals in devices like smartphones and Wi-Fi systems. They rely on the propagation of sound waves through a material to achieve this filtration.

What are atomic vacancies?

Atomic vacancies are defects in a crystal lattice where an atom is missing. In the context of this research, atomic vacancies in silicon carbide play a crucial role in measuring the stability of acoustic resonators and controlling quantum states.

What is quantum information processing?

Quantum information processing is a field of study that focuses on using the principles of quantum mechanics to manipulate and process information. It leverages the unique properties of quantum systems, such as superposition and entanglement, to perform computations more efficiently than classical computers.

How can this research benefit accelerometers, gyroscopes, clocks, and quantum networking?

By monitoring the stability and quality of acoustic resonators, this research can help improve the performance and longevity of devices such as accelerometers, gyroscopes, and clocks. Additionally, the ability to control quantum states opens up new possibilities for quantum networking, where information can be processed and transmitted at the quantum level for enhanced security and computational power.