A team of scientists from several institutions, guided by physicist Peng Wei from the University of California, Riverside, has invented a new superconductor material that may have applications in quantum computing and could be classified as a “topological superconductor.”
Led by physicist Peng Wei from the University of California, Riverside, a collaborative team of researchers across various institutions in the United States has created a novel superconductor material that holds promise for use in quantum computing and is being explored as a potential “topological superconductor.”
Topology, the mathematics of shape, plays a key role here. A topological superconductor can utilize a delocalized electron or hole (the latter acting like a positively charged electron) to transport quantum information and manage data in a stable manner.
In their report published today in Science Advances, the researchers describe how they fused trigonal tellurium with a superconductor created at the surface of a thin gold film. This unique material, trigonal tellurium, is chiral, meaning it cannot be mirrored onto itself, much like our hands. Additionally, it lacks magnetic properties. Remarkably, the team discovered quantum states at the interface that exhibited clear spin polarization, providing a framework for creating a spin quantum bit, or qubit.
“By establishing a very clean interface between the chiral material and gold, we created a two-dimensional interface superconductor,” stated Wei, an associate professor of physics and astronomy. “This interface superconductor is distinctive because its spin energy is enhanced sixfold compared to regular superconductors.”
The researchers noticed that under a magnetic field, the interface superconductor transitions to a more robust state at higher fields, indicating a shift into a “triplet superconductor,” which shows greater stability in magnetic conditions.
Moreover, in partnership with scientists from the National Institute of Standards and Technology, they found that their heterostructure combining gold and niobium thin films effectively diminishes decoherence caused by material flaws like niobium oxides, a frequent issue with niobium superconductors. They demonstrated that this superconductor can be transformed into high-quality, low-loss microwave resonators, achieving a quality factor as high as 1 million.
This innovative technology has significant implications for quantum computing, a field that leverages the principles of quantum mechanics to tackle complex challenges that classical computers struggle to address efficiently, as stated by the multinational tech firm IBM.
“We accomplished this using materials that are much thinner, by an order of magnitude, than those conventionally applied in quantum computing,” Wei explained. “These low-loss microwave resonators are vital elements in quantum computers and could pave the way to low-loss superconducting qubits. One of the main hurdles in quantum computing is minimizing decoherence or the loss of quantum information within a qubit system.”
Decoherence arises when a quantum system interacts with its surroundings, leading to a loss of clarity as the system’s information becomes entangled with external factors. This phenomenon presents a significant barrier to developing functional quantum computers.
In contrast to earlier techniques that rely on magnetic materials, the new method employed by the researchers utilizes non-magnetic materials to ensure a cleaner interface.
“Our material represents a promising option for advancing more scalable and dependable components for quantum computing,” said Wei.
Wei’s graduate students at UCR also contributed to this research.
The research paper is titled “Signatures of a Spin-Active Interface and Locally Enhanced Zeeman Field in a Superconductor-Chiral Material Heterostructure.”
Wei’s NSF CAREER award, a NSF Convergence Accelerator Track-C grant shared between UCR and MIT, as well as a Lincoln Lab Line fund also shared by UCR and MIT, supported the UCR segment of the study.
This technology has been reported to the UCR Office of Technology Partnerships, and a provisional patent has been submitted.
The University of California, Riverside (UCR) is a doctoral research university that serves as a hub for groundbreaking research on vital issues affecting Inland Southern California, the state, and global communities. UCR’s enrollment exceeds 26,000 students, reflecting California’s rich cultural diversity. The campus inaugurated a medical school in 2013 and has extended its reach into the Coachella Valley through the UCR Palm Desert Center. Annually, UCR contributes over $2.7 billion to the U.S. economy. For further information, visit www.ucr.edu.
