Scientists Capture Sound Making Quantum Jumps for the First Time — A New Era for Quantum Technology

For the first time, scientists have directly watched sound make a quantum jump — suddenly moving from one energy state to another instead of changing gradually.

Researchers at Stanford University have recorded individual quantum states of sound in real time, observing a single phonon disappear as the system moved from an energy state of 1 to 0. The breakthrough provides scientists with a new way to study quantum mechanics and could eventually contribute to quantum computing, error correction, ultra-sensitive sensors and advanced sound-based technologies.

The findings, published in Science, represent an important step in understanding how familiar things such as sound behave at the smallest possible scales.

What Is a Quantum Jump?

In everyday life, changes usually appear continuous. For example, when a bell rings, its sound slowly becomes quieter until it eventually disappears.

Quantum physics tells a different story.

At the quantum level, energy does not always change smoothly. Instead, a system can exist in specific energy states and suddenly move from one state to another. These sudden changes are known as quantum jumps.

Scientists have studied such behavior for decades. Quantum jumps were first demonstrated experimentally in trapped ions in 1986. Researchers later observed similar behavior in photons, the basic particles of light.

Sound, however, was much harder to observe in the same way.

Now, a team led by Stanford physicist Amir Safavi-Naeini has directly observed these quantum jumps in a mechanical resonator.

“What this study shows will allow us to move forward with developing new quantum technologies with sound,” Safavi-Naeini said.

Sound Has Its Own Quantum Particle

To understand the experiment, it helps to look at how sound works in quantum physics.

Light is made up of tiny packets of energy called photons. The quantum equivalent for sound is called a phonon.

A phonon is not a tiny piece of sound traveling through the air. Instead, it represents a quantized vibration — the coordinated movement of many atoms in a material.

At normal scales, vibrations appear continuous. But inside the tiny mechanical device used in this experiment, the researchers could observe vibration energy changing in individual quantum steps.

This allowed them to watch something that sounds almost impossible in everyday life: a single quantum of vibration suddenly disappearing from one energy state.

A Tiny Device That Can Keep Ringing

The researchers created a microscopic mechanical resonator using techniques similar to those used to manufacture computer chips.

The device works somewhat like an extremely small tuning fork. When it vibrates, it stores mechanical energy.

But there was an important challenge. Quantum states are extremely delicate and can disappear very quickly.

The researchers therefore needed a resonator capable of maintaining its vibration for an unusually long time.

Their device could continue vibrating for about two milliseconds.

That may sound incredibly short, but at the microscopic quantum scale, it is remarkably long.

The researchers compared its performance to a normal tuning fork. If an ordinary tuning fork could maintain vibrations with the same relative efficiency, it would continue ringing for several hours.

This long-lasting vibration gave the team enough time to repeatedly measure the system and collect hundreds of observations.

How Scientists Watched the Quantum Jump

Observing a quantum system is not easy because the act of measuring it can disturb it.

The researchers solved this problem by connecting the mechanical resonator to a superconducting qubit.

A qubit is a quantum system that can store information. In this experiment, it also worked as a highly sensitive detector.

The qubit repeatedly checked the mechanical resonator during its vibration. It could determine whether the phonon was in one energy state or another.

By performing these measurements again and again, the researchers were able to identify when the quantum system suddenly changed.

Instead of simply seeing evidence that quantum jumps had happened, they could track the jumps in real time.

That is what makes the new experiment particularly significant.

Why This Matters for Quantum Computing

One of the most promising areas for this discovery is quantum computing.

Quantum computers work with delicate quantum states. These states can be disturbed by their surroundings, creating errors during calculations.

Detecting these errors quickly is one of the major challenges facing quantum computing.

Quantum jumps can provide information about when a quantum system has changed unexpectedly. If scientists can reliably detect and monitor such changes using mechanical vibrations, it could eventually help researchers develop new approaches to quantum error detection and correction.

The Stanford experiment does not mean that sound-based quantum computers are ready for practical use. Instead, it demonstrates an important capability: scientists can now precisely observe and control quantum behavior in mechanical vibrations.

That could provide another platform for developing future quantum technologies.

Could It Help Detect Proteins Inside Cells?

The potential applications may also extend beyond computing.

Mechanical resonators are extremely sensitive to changes in their environment. Even a tiny change in mass or vibration can affect how such a device behaves.

Because of this sensitivity, researchers are exploring whether similar systems could eventually be used as highly precise sensors.

Safavi-Naeini's team is already working with researchers at Caltech to investigate whether this technology could help detect and identify proteins inside cells.

Such technology could potentially give scientists new ways to study biological processes at extremely small scales.

Better Control of Sound

The discovery could also have implications for technologies that already rely on vibrations and sound.

Sound and mechanical vibrations are used in many modern electronic devices, including components found in smartphones and other technologies.

If scientists gain greater control over sound at the quantum level, it could eventually lead to improvements in devices that use mechanical vibrations as part of their operation.

However, these applications are still a long way from becoming everyday products.

The immediate importance of the research is more fundamental: it shows that scientists can observe, measure and control individual quantum states of mechanical sound.

A New Way to Explore the Quantum World

Quantum physics has repeatedly shown that the familiar rules of everyday life do not always apply at extremely small scales.

Sound normally seems like something that gradually fades away. But at the quantum level, its energy can change in discrete steps.

The Stanford experiment provides scientists with a direct view of this behavior.

The work also brings together two very different technologies — a tiny mechanical resonator and a superconducting qubit — to create a system capable of detecting incredibly small changes in vibration.

For now, the discovery is primarily a breakthrough in fundamental quantum science. But by showing that sound can be controlled and monitored at the level of individual phonons, researchers have opened another possible path toward future quantum computers, precision sensors and advanced technologies.

The next challenge will be learning how to control these quantum states more precisely and use them for useful tasks.

In other words, scientists have not simply made sound behave strangely. They have gained a new way to see the quantum world — one tiny vibration at a time.

Reference:

1. Takuma Makihara, Erik Szakiel, Matthew P. Maksymowych, Oliver A. Hitchcock, Kaveh Pezeshki, Rachel G. Gruenke-Freudenstein, Mihir Pendharkar, Shannon P. Harvey, David I. Schuster, Amir H. Safavi-Naeini. Quantum jumps of sound. Science, 2026; 393 (6817): 1217 DOI: 10.1126/science.aeh7535