Researchers have demonstrated a new fabrication approach that enables the exploration of a broader range of superconducting materials for quantum hardware.
The study, published in Applied Physics Letters and selected as a "Featured" article, addresses a long-standing challenge: many promising superconductors, such as transition metal nitrides, carbides, and silicides, are difficult to pattern into functional devices using conventional chemistry-based methods.
By showing that physical patterning provides a viable alternative, the study paves the way to evaluate and harness these materials for high-performing quantum technologies.
The team, led by NYU Tandon professor Davood Shahrjerd i, demonstrated that one such technique, called low-energy ion beam etching (IBE), can be used to fabricate high-performing quantum devices. They validated the approach using niobium, a well-studied superconductor, and benchmarked the resulting devices against state-of-the-art counterparts made with conventional chemistry-based methods, showing comparable performance.
Quantum computers have the potential to tackle problems that are intractable for today's machines, with applications in drug discovery, cryptography, and financial modeling.
"Realizing this promise requires components that can preserve fragile quantum states long enough to perform complex calculations," said Shahrjerdi. "That means building ever more perfect hardware to reduce errors and improve the fault tolerance of quantum systems."
The team's demonstration advances this broader goal by expanding the superconducting material toolkit for device fabrication.
"Fabricating devices with materials-agnostic techniques expands the design space for quantum hardware to under-explored materials, which could catalyze advancements in the scaling of quantum information systems to greater size and functionality," said Dr. Matthew LaHaye, a research physicist at the Air Force Research Laboratory (AFRL) and a collaborator on the project.
To put this approach to the test, Ph.D. students Miguel Manzo-Perez and Moeid Jamalzadeh , co-lead authors of the study, designed superconducting resonators and developed fabrication protocols that combined electron-beam lithography with IBE. They deposited thin niobium films on silicon substrates and patterned them into superconducting resonators, completing the entire process at the NYU Nanofabrication Cleanroom (NYU Nanofab) , the first academic cleanroom in Brooklyn.
"NYU Nanofab is equipped with state-of-the-art tools and a strategic focus on enabling the fabrication of advanced devices from quantum materials and superconductors," said Shahrjerdi, the inaugural Faculty Director. "In addition to advancing academic research, it also serves as the prototyping facility of the Northeast Regional Defense Technology (NORDTECH) Hub, with the mission to support lab-to-fab transitions in superconducting quantum technologies."
Next, the devices were shipped to AFRL, where Booz Allen Hamilton contractors Christopher Nadeau and Man Nguyen tested them at temperatures near absolute zero. The quantum resonators demonstrated high performance, confirming the feasibility of the IBE-based fabrication approach for realizing low-loss quantum hardware.
Loss is a critical measure of hardware quality, with lower values indicating more perfect superconducting devices.
In addition to Shahrjerdi, LaHaye, Manzo-Perez, Jamalzadeh, Nadeau, and Nguyen, the other co-authors of the paper include Alexander Madden of Booz Allen Hamilton; Iliya Shiravand of NYU Tandon; Kim Kisslinger and Xiao Tong of Brookhaven National Laboratory; Kasra Sardashti of the University of Maryland; and Michael Senatore of the Air Force Research Laboratory.
NYU Tandon and AFRL Rome collaborate under a Cooperative Research and Development Agreement (24-RI-CRADA-09) and are supported by funding from the Microelectronics Commons through the Northeast Defense Technology Hub project entitled "Improved Materials for Superconducting Qubits with Scalable Fabrication."
