Scientists have discovered an exciting new way to control the behavior of tiny particles in a special material called perovskite, which could be used in future quantum technologies.
These materials, already known for their use in solar panels, might also help create quantum computers and sensors for extremely precise measurements.
The key to this discovery is something called “spin,” a special property of electrons.
In atoms, electrons orbit the nucleus, and when two atoms are close together, they can share electrons, forming a bond.
The shared electrons have one of two spin states: “spin up” or “spin down.”
These spin states are important because scientists want to control them for new types of technology, like quantum computing and spintronics.
Researchers from the U.S. Department of Energy’s Argonne National Laboratory and Northern Illinois University have found a way to use light to detect and control the spin states in a perovskite material called methylammonium lead iodide (MAPbI3).
Their study, published in Nature Communications, shows how this discovery could lead to the development of advanced quantum devices.
Normally, when light hits perovskite, it excites one of the electrons, making it jump to a higher-energy level and leaving a “hole” behind. This creates a particle called an exciton, which consists of the excited electron and the hole. But excitons usually don’t last long, as the electron quickly falls back into the hole, releasing light in the process.
However, the researchers found that by adding a rare earth metal called neodymium to the perovskite material, they could extend the lifetime of excitons by more than 10 times. Neodymium has unpaired electrons that can interact with the electrons in the exciton, creating a special state called “spin entanglement.” This means that even though the electron and its partner hole are separated, they can still influence each other.
By adjusting the amount of neodymium in the material, the scientists were able to detect the spins of the excitons. This is exciting because it could allow them to entangle multiple electron spins, which is a key ingredient for creating qubits—the building blocks of quantum computers.
Unlike classical computers that use bits to represent either a 0 or 1, qubits can represent both at the same time, making quantum computers far more powerful in certain tasks.
This discovery could also lead to the development of quantum sensors, which could measure things like magnetic fields or temperature with extreme precision. The researchers hope that by continuing to study this material, they can unlock even more possibilities for quantum technology.
