The next phase of quantum energy science: from mechanisms to applications

For decades, the most famous application of quantum mechanics has been the manipulation of information. Scientists have learned to trap atoms and superconducting circuits to act as tiny switches, storing bits of data in delicate states of existence that can be read, copied, or erased. This field, known as quantum information science, treats the quantum state as a fragile vessel that must be kept perfectly intact, like a glass sculpture that shatters if touched too roughly. However, the same physical systems that hold information also hold energy. A single atom can be excited to a higher energy level, storing a packet of power just as it might store a piece of data. The crucial difference is that while information often requires perfect preservation, energy does not. A quantum system can lose its delicate phase coherence—the synchronized rhythm that makes it useful for computing—and still retain its stored energy, ready to be released later. This realization has sparked a new way of thinking about how we might harness the quantum world, not just to compute, but to power, store, and direct energy with unprecedented precision.

A team of researchers from the Massachusetts Institute of Technology and institutions across the globe has now organized these scattered efforts into a coherent field they call quantum energy science. Their work moves beyond looking at specific applications like solar panels or nuclear batteries and instead focuses on the fundamental operations that any energy system must perform. They propose that all energy management, whether in a molecule, a circuit, or an atomic nucleus, boils down to five basic actions: getting energy into a system, holding onto it, letting it out, moving it from one place to another, and changing it into a different form. By breaking the problem down into these elementary steps, the researchers have created a universal language that connects disparate fields, from the study of light-harvesting plants to the control of nuclear reactions.

The researchers argue that the key to this new science is the deliberate engineering of how quantum states interact. In the past, scientists often fought against the environment, trying to isolate systems to prevent energy from leaking away. This new approach suggests that the environment can be a tool. By carefully designing how a system connects to its surroundings, scientists can actually use the environment to speed up charging, protect stored energy, or guide it to a specific destination. For example, they can arrange many atoms to act in unison, allowing them to absorb energy much faster than they could alone, or they can create "dark" states where energy is trapped safely, invisible to the channels that would normally let it escape. This is not about preserving a perfect quantum state forever; it is about using the rules of quantum mechanics to control the flow of power.

To understand how this works, the authors describe a framework that links the microscopic mechanisms to real-world capabilities. They identify five elementary functions. The first is "Excite," which is simply the act of pumping energy into a system, such as using a laser to push an electron to a higher energy level. The second is "Hold," which involves keeping that energy there without it leaking away. This is often the hardest part, as nature prefers to let excited states relax back to their calm, low-energy state. The third is "Release," the controlled opening of a valve to let that stored energy out to do work. The fourth is "Transfer," which moves energy from one part of a system to another without it ever leaving the system boundary. The final function is "Transform," where the energy changes its nature, such as turning light into electricity or triggering a chemical reaction.

These functions are not just theoretical concepts; they are being tested in laboratories with real materials. At the molecular scale, researchers have shown that by placing molecules inside tiny optical cavities, they can create collective states where the molecules absorb light much more efficiently than they would on their own. In one experiment, a film of organic molecules was charged in less than a trillionth of a second, a speed far beyond what is possible with individual molecules. Other work has demonstrated how to store energy in long-lived molecular states, keeping it safe for microseconds before releasing it as an electrical current. These are small steps, but they prove that the basic functions can be engineered.

The challenge becomes even more complex when moving to the scale of the atomic nucleus. Nuclei contain vastly more energy than electrons, but they are also much harder to reach. While a laser can easily excite an electron, exciting a nucleus often requires high-energy X-rays or gamma rays, which are difficult to produce and control. However, the researchers point out that some nuclear states are naturally very stable, holding their energy for years or even centuries. The goal is to find a way to load these nuclear "batteries" and then release that energy on demand. One promising avenue involves using the 229Th isotope, which has a nuclear transition at a relatively low energy that can be reached with lasers. Scientists have already demonstrated that they can excite this nucleus and that the energy can be stored for hundreds of seconds. The next step is to figure out how to release that energy efficiently, perhaps by using the surrounding electrons in the crystal to help trigger the release.

The paper also explores how these functions can be combined to create three major engineering capabilities: storage, routing, and conversion. Storage is the ability to keep energy and retrieve it later. While current quantum batteries are far from replacing the lithium-ion cells in our phones, the researchers suggest that nuclear storage could one day offer energy densities thousands of times higher than chemical batteries, with the ability to hold that energy for years without loss. Routing is the ability to direct energy to a specific destination. In nature, plants are masters of this, guiding energy from light-harvesting antennas to reaction centers with near-perfect efficiency. The researchers are working to replicate this in artificial systems, using shared modes of light or vibration to guide energy between molecules or even between distant nuclear spins. Conversion is the ability to change energy from one form to another, such as turning nuclear energy into electricity or steering a chemical reaction to produce a specific product.

The authors are careful to note that while the physics is sound, the engineering is still in its infancy. They present a set of "stretch scenarios" to illustrate what success might look like in the next decade or two. One possibility is a quantum processor that uses a shared pool of energy to power its operations, reducing the need for complex wiring and cooling. Another is a nuclear battery that could power a spacecraft for decades, recharging its energy only when needed. There are also visions of chemical factories where light is used to steer reactions, producing only the desired product and eliminating waste. These are not guaranteed outcomes, but they represent the kind of performance targets that would make the technology truly useful.

What makes this work significant is not just the specific results, but the new way of thinking it offers. By focusing on the functions of energy rather than the specific materials, the researchers have created a map that connects communities that rarely speak to one another. A scientist working on solar cells, another on nuclear physics, and a third on quantum computing may all be solving the same fundamental problem: how to get energy into a system, keep it there, and get it out where it is needed. This shared vocabulary allows them to learn from each other's successes and failures. For instance, the techniques used to protect a nuclear state from decaying might inspire new ways to protect an electron in a solar cell.

The path forward will require testing these ideas under realistic conditions. Theoretical models suggest that collective effects can speed up charging, but real-world disorder and noise might interfere. The researchers emphasize that the goal is not to achieve perfect quantum coherence at all costs, but to find the right balance where quantum effects provide a practical advantage. They suggest that the environment, often seen as an enemy, can be engineered to help. By shaping how a system interacts with its surroundings, scientists can suppress unwanted energy loss or guide energy along specific paths. This shift from fighting nature to working with it is the core of the new approach.

Ultimately, the paper argues that quantum energy science is maturing into a distinct field with its own goals and methods. It is no longer just about applying quantum mechanics to existing energy problems; it is about reimagining how energy itself can be managed at the most fundamental level. The researchers have laid out a framework that connects the microscopic world of quantum states to the macroscopic world of useful devices. While the journey from the laboratory to the power grid is long, the first steps are being taken. By mastering the five elementary functions of energy, humanity may one day unlock new ways to store, move, and use the power that resides within the very fabric of matter.