The field of quantum computing may have just received a boost in coherence and error prevention in the form of parafermions: Grouped electrons that behave as a liquid in a special state of matter.Scientist at Nanyang Technological University in Singapore (opens in new tab) We have shown experimental results that are expected to lead to parafermions when electrons maintain a temperature close to absolute zero (-273 degrees Celsius). This research achieved a breakthrough by demonstrating that there are conditions under which electrons can have strong interactions. This is just what scientists have theorized so far.
The orderly movement of electrons results in what we know as electricity. But even though the electrons move in this “regular” pattern, they really don’t. Because they are negatively charged, the electrons tend to repel each other and move in different directions (like gases) individually and haphazardly rather than as a cohesive whole. They are like disabled drivers. There may be some “steps” on the way to the destination. But when the electron behaves like a liquid, it’s like swapping a faulty driver for a good one. Drivers who know and respect each other’s boundaries, speed and direction to reduce collisions and reach their destinations better.
Of course, drivers like these are the subject of much theoretical thought, but at least now, experimental evidence has shown that strong electronic interactions exist.
When the electrons are forced to act in what is known as a ‘spiral Tomonaga-Luttinger liquid’, there is less particle interaction and energy exchange between the electrons and the system. This reduces the amount of systematic and environmental interference that often causes quantum system errors and quantum state collapse. Electrons, previously cooled to near absolute zero, are also an essential element. This allows certain materials to achieve a superconducting state, allowing electrons to traverse the surface without electrical resistance, further reducing potential environmental interference factors. A system cooled to absolute zero (4.5 Kelvin or -269 degrees Celsius in our experiments) forces the particles to slow down, rendering them nearly immobile.
Electrons (and their spin properties) have been used as quantum programmable particles for some time. Thus, improved electronic control leading to reduced disturbances means reduced errors and improved coherence. This means that the actual qubits that can store or process information have a longer lifetime. In fact, certain quantum systems (such as IBM’s Quantum One and Quantum Two) already utilize superconducting qubits.
In this case, the scientists used atomically thick graphene substrates to deposit atomically thick crystals of tungsten ditelluride. This is a nearly two-dimensional material known as a ‘quantum spin Hall insulator’ that is gravity-insulating on the inside but has electrons on its surface. outside. After combining the graphene/tungsten ditelluride substrate and cooling it to absolute zero, the researchers placed it under a scanning tunneling microscope just 1 nanometer from its surface. It was smaller than a strand of DNA and the smallest transistor ever made. See what drives the latest and greatest graphics cards).
When placed under a scanning tunneling microscope and cooled to absolute zero, the researchers noticed that the electrons within the graphene/tungsten substrate increased their repulsion. Their repulsive forces were so strong that the interaction between the repulsive fields of each electron forced them to move collectively. The researchers registered Rattinger parameters within the range of 0.21 to 0.33. This parameter represents the strength of interactions between particles. When it reaches 1, the interaction is the weakest.
“If the Luttinger parameter is less than 0.5, the interaction becomes stronger and the electrons are forced into collective motion. This is the region where we would expect parafermions to exist,” says Weber. “The Luttinger parameter only fits between 0 and 1, so this is a really remarkable range of variation,” he continued. “Control of the Luttinger parameter at such low values has never been observed in spiral Tomonaga-Luttinger liquids.”
The team now plans to take advantage of NTU Singapore’s new ultra-low-vibration lab, built earlier this year, to further reduce temperatures. In the laboratory, experiments can be performed at temperatures as low as 150 milliKelvin (mK). This will allow researchers to see stronger repulsions between electrons and real sightings of parafermionic groups.
Interestingly, the researchers’ approach seems somewhat related to Microsoft’s own race to implement so-called topological qubits and their necessary (and not yet working) Majorana modes.