In the world quantum physics, it seems that another record has just been broken. In paper listed on the ArXiv preprint page, scientists from the China University of Science and Technology say they observed atoms in a state of quantum superposition for 23 minutes. They argue that the ability to maintain stable quantum states for such a long time could lend a hand enhance the durability of quantum devices and discover strange modern effects in quantum physics.
Superposition is a phenomenon in which an object can occupy many different states at any given time, but the actual state of the object is unknown. Very tiny objects such as photons or electrons exhibit this behavior; they behave like waves, potentially occupying multiple positions at once, rather than as particles with a single position. Most importantly, when we observe an object in superposition, its state collapses and it is only evident in one of its potential states. You can think of it like flipping a coin – as it spins in the air, it’s potentially heads or tails at the same time, but when you look at it after it lands, it may only be one tail or the other.
You may also have heard of superposition being explained using the notable Schrödinger’s cat paradox. This was a thought experiment proposed by physicist Erwin Schrödinger in which a cat is placed in a sealed box with radioactive material that will randomly decompose, which, if it dies, kills the cat. Until you open the box, the experiment suggests that the cat is in a superposition, being both alive and dead. The Schrödinger experiment, although commonly used to explain superposition, was intended to demonstrate the apparent absurdity of this quantum behavior.
Over the years, researchers have been able to spot diminutive objects that exhibit superposition, with featherlight particles and even diminutive crystals in the lab being shown to occupy multiple states at once. However, the objects in these experiments were always very unstable and their exposure to superposition extremely fleeting. But in a modern study, Chinese researchers led by physicist Zheng-Tian Lu apparently used atoms trapped by featherlight to sustain the phenomenon.
The researchers used about 10,000 ytterbium atoms, which they cooled to a few thousandths of a degree above absolute zero and trapped them using the electromagnetic forces of laser featherlight. Under these conditions, the quantum states of the atoms could be controlled very precisely, which scientists used to place each atom in a superposition of two concurrent states that had two very different spins.
Generally speaking, disturbances from the atoms’ environment would cause them to collapse into one state within seconds or milliseconds, but the researchers managed to fine-tune the lasers to hold them for an unprecedented 1,400 seconds, or 23 minutes. However, it is significant to note that the work has not yet been formally independently peer-reviewed.
Because it extends the superposition for so long, such a technique, if proven possible, could in the future be used to detect and study magnetic forces, study modern and exotic phenomena in physics, and even enable the creation of highly stable quantum computer memory.
This story originally appeared on WIRED Italy and was translated from Italian.