We're edging closer to quantum.
A team of scientists just experimentally proved the existence of a new kind of quasiparticle, which could bring us one substantial step closer to the metamaterials needed to run quantum computers, according to a recent study published in the journal Physical Review B.
We're not there yet, but using artificial matter like this could help fill in even more "theoretical gaps" for real-world quantum computers.
Metamaterial quantum simulators can discover properties that don't exist in nature
If we're going to build quantum computers, we'll likely do so with superconducting qubits. But the next-gen computer tech is highly affected by decoherence, which snubs the lifespan of qubits, leading to computational errors. Additionally, large qubit arrays are remarkably difficult to control. This is why metamaterial quantum simulators offer a unique perspective to researching and developing quantum computing, since they aren't needed in large quantities to exercise control of electronics. The metamaterial quantum simulator method involves creating artificial matter from qubits, and these synthetic ones still follow the same governing laws described in equations that real-life matter does. On the other hand, scientists can program the simulator such that a simulator may embody matter with novel properties that no one has ever seen in nature.
Superconducting qubit arrays are described by the Bose-Hubbard model, which presents bound boson pairs, also called doublons, and these are the result of strong quantum nonlinearity. "The topological physics of doublons has been extensively explored in a series of recent theoretical works," read a blog post on Russia's National University of Science and Technology (NUST) official website. "However, the experimental investigation of topological properties of bound photon pairs is still lacking." The team of scientists, stemming from NUST MISIS, the Russian Quantum Center, Bauman Moscow State Technical University, ITMO University, Dukhov Automatics Research Institute (VNIIA), and Ioffe Institute, together employed a superconducting array of qubits to design and build a quantum simulator.
Russian physicists proved that 'doublon topological excitations' exist
"By registering the properties of qubits, we can draw conclusions about a broader class of physical systems described by the same equations," said Junior Researcher Ilya Besedin of the NUST MISIS Laboratory of Superconducting Metamaterials, in the blog post. "And if we change the parameters of these equations in a controlled way, then such a device can be considered a 'specialized simulator'." This won't engender an exact match to a real-world quantum computer, "but its scaling requires significantly fewer resources." The experiment ultimately revealed that doublons can also form an "edge state."
"We were able to see how doublons form these zones, and we even managed to detect how an edge doublon state appeared at the upper edge of the doublon zone as we increased the length of the array," added Besedin in the blog post. This is an impressive development, since it constitutes the first demonstration that a novel kind of quasiparticle, called doublon topological excitations, can come into being amid qubit chains. Teams of physicists are currently analyzing superconducting qubits and quantum circuits worldwide, and this latest study brings the world of scientists and several industries closer than ever before to viable quantum computing technology.