“Revolutionary Superconductor Set to Boost Quantum Computer Performance”

Superconductor Set to Turbocharge Quantum Computers

Physicists have engineered a revolutionary superconductor material poised to transform the scalability and dependability of quantum computing components.

By fusing trigonal tellurium with a gold thin film, they have created a two-dimensional interface superconductor exhibiting enhanced spin polarization, indicating potential for generating stable spin qubits.

The material’s transition in the presence of a magnetic field suggests its suitability as a triplet superconductor, potentially yielding more resilient quantum computing components.

Additionally, this novel superconductor technology inherently mitigates decoherence—a major obstacle in quantum computing—by employing non-magnetic materials to achieve cleaner interfaces.

Pioneering Superconductor Discovery in Quantum Computing

A team of U.S. scientists, led by physicist Peng Wei at the University of California, Riverside, has developed a new superconductor material with significant implications for quantum computing, positioning it as a candidate for a “topological superconductor.”

In mathematical terms, topology deals with the properties of shape. A topological superconductor utilizes a delocalized electron or hole state to robustly carry quantum information and process data.

Chiral Material and Interface Superconductivity

As reported in Science Advances on August 23, the researchers have combined trigonal tellurium—a chiral, non-magnetic material—with a surface state superconductor formed on a thin gold film.

Chiral materials, like trigonal tellurium, cannot be superimposed on their mirror images, much like left and right hands.

Remarkably, the researchers observed quantum states at the interface that exhibit distinct spin polarization, which could be harnessed to create a spin quantum bit, or qubit.

Spin Polarization and Qubit Potential

“We developed a two-dimensional interface superconductor by creating a pristine interface between the chiral material and gold,” said Wei, an associate professor of physics and astronomy.

“This interface superconductor is exceptional, existing in an environment where the spin energy is amplified sixfold compared to conventional superconductors.”

The researchers noted that this interface superconductor undergoes a transition when exposed to a magnetic field, becoming more robust at higher fields—a characteristic indicative of a transition into a “triplet superconductor,” known for its stability under magnetic influence.

Suppressing Decoherence in Quantum Computing

Collaborating with experts from the National Institute of Standards and Technology (NIST), the team demonstrated that this superconductor, involving a heterostructure of gold and niobium thin films, naturally suppresses decoherence from material defects like niobium oxides—a common issue with niobium superconductors.

The superconductor was crafted into high-quality, low-loss microwave resonators with a quality factor reaching 1 million.

Implications for Quantum Computing Technology

This innovative technology holds significant promise for quantum computing, a field leveraging quantum mechanics to tackle complex problems that classical computers struggle to solve or solve efficiently, as highlighted by multinational tech giant IBM.

“We achieved this with materials an order of magnitude thinner than those typically utilized in the quantum computing industry,” Wei remarked.

“These low-loss microwave resonators are critical for quantum computing and could pave the way for low-loss superconducting qubits. The primary challenge in quantum computing is mitigating decoherence or the loss of quantum information within a qubit system.”

Decoherence, which occurs when a quantum system interacts with its surroundings, results in the entanglement of the system’s information with the environment, posing a significant hurdle for the realization of quantum computers. Unlike earlier approaches that required magnetic materials, the researchers’ new technique employs non-magnetic materials, ensuring a cleaner interface.

A Promising Horizon for Scalable Quantum Components

“Our material stands as a promising candidate for developing more scalable and reliable quantum computing components,” Wei concluded.

Reference

“Signatures of a Spin-Active Interface and Locally Enhanced Zeeman Field in a Superconductor-Chiral Material Heterostructure,” August 23, 2024, Science Advances. DOI: 10.1126/sciadv.ado4875.

Wei’s research was supported by his graduate students at UCR. The UCR contribution was funded through Wei’s NSF CAREER award, an NSF Convergence Accelerator Track-C grant shared by UCR and MIT, and a Lincoln Lab Line fund shared by UCR and MIT. The technology has been disclosed to the UCR Office of Technology Partnerships, with a provisional patent filed.

Superconductor Set to Turbocharge Quantum Computers