Quantum technologies, the effects of which are predicted to be revolutionary, depend critically on the ability to convey and store information reliably. In the future, quantum computers can answer the most challenging problems that ordinary computers have been unable to solve for thousands of years in only a few hours.
However, storing information in a quantum state presents several challenges. Qubits, the data units used to store quantum information, are very fragile packages. The qubit is easily destroyed by even the slightest environmental perturbation.
Material scientist Feng Pan designed objects with sculptural qualities that affect light to encode information. The postdoctoral researcher at Stanford University predicted that using polaritons will be powerful and essential for information storage. They’re helpful because we can put more data in them.
To safeguard the delicate qubits, Pan is building his metamaterials for Q-NEXT so that he has precise control over the way they produce photons. Photons are particles of light and bearers of quantum information. Q-NEXT is a National Quantum Information Science Research Centre funded by the U.S. Department of Energy and led by Argonne National Laboratory, where Pan is a member.
Pan intended the material to provide particles with well-delineated chirality, denoting the particle’s inherent right- or left-handedness. Pan wanted to create chiral polaritons, which are half-light and half-matter particles. Unlike photons, these particles may move and interact with one another. It plays a crucial role in quantum computing and the modelling of quantum systems.
Polaritons, which can only be left- or right-handed, gain chirality thanks to Pan’s metamaterials. Flawed, unreliable chirality is unacceptable. This feature provides researchers with a crucial new dial to adjust when tinkering with quantum memory.
Light is manipulated by matter’s structure. The iridescence is caused by the opal’s bending and curving of light. When seen via a prism, its various colours are revealed. A reflection in a mirror flattens the 3D image. His materials aren’t light refracting like opals or prisms. His 2D etchings are only visible with a high-powered microscope. These minuscule bas reliefs securely store and transmit quantum information, and they do it by employing the properties of metamaterials, which are materials showing behaviours do not present in nature.
With 1/1,000th the width of a human hair, Pan’s metamaterials include notches, carvings, and formations with entertaining names like “nano bars” and “nanodiscs.” The end product frequently resembles a nanoscopic apple pie that has been partially devoured.
Despite the light-hearted language used to describe them, the design of these elements is meticulous. They can manipulate light in non-standard ways, such as bending or redirecting it, and they can store the energy of light for a very long period (in the quantum world)—a millionth of a second.
To characterise these materials think the best way is to experiment with the optics and build the setup. Pan used a three-stage procedure to make his metamaterials. First, they begin by designing the metamaterials using computer-aided numerical simulations.
Second, he made them in a sterile environment. He prints the 2D design onto a unique chemical by defining it with an electron beam. Next, the plan is transferred to a layer of silicon just hundreds of nanometers thick, or about 1/1,000th the thickness of a sheet of paper. A second layer of atomically thin semiconductor material is included in the metamaterial.
Third, he and his group tracked the overall performance metrics. What properties do the photons it emits have? Is there a way to make it better? How? After making some changes to the design, the team starts over again from the beginning. Optimisation of the entire process may take many weeks or months.
Pan feels the most striking feature of the study is the ability to tailor the chirality of the metamaterials and then link them to other materials to generate chiral polaritons.
