George Mason University Physicist Awarded NSF CAREER Grant for Topological Quantum Computing Innovations

In 2023, Ghahari was the first faculty member at George Mason to receive the competitive U.S. Department of Energy (DOE) Early Career Award to advance quantum technologies, and now she is the first to receive CAREER awards from both the DOE and NSF.

Ghahari’s study “Topological order and edge states in fractional quantum Hall systems” will focus on the complex quantum phases in graphene materials, which could be utilized in the development of future quantum technologies. For this project, Ghahari will investigate a specific topological phase of matter known as the fractional quantum Hall effect, which she first discovered in graphene in 2009. This phenomenon that appears in two-dimensional electron systems under high magnetic fields and ultra-low temperatures can support new particles that serve as the building blocks for topological quantum computers.

“By looking at how the charges flow and the heat they carry in response to a temperature gradient, we can measure entropy, or the degree of randomness, which can reveal the topological properties of these new particles and if they can be used in future topological quantum computers,” she explained.

Topological quantum computers allow for complex calculations out of reach of standard computing schemes. Quantum bits (qubits), which are used in conventional quantum computing, are more susceptible to errors due to environmental noise and other factors. Topological qubits, however, are prone to these types of errors.

“Studying these specific phases may also provide valuable insights into one of the long-standing problems in cosmology known as the “blackhole paradox” that addresses the loss of information in blackholes,” Ghahari said.

“Ghahari’s research and programmatic efforts continue to receive well-deserved attention,” said Department of Physics and Astronomy Chair Ernest Barreto. “Our quantum computing and materials academic offerings and research support continue to grow, thanks to such innovative research, outreach, and partnerships,” Barreto said.

Students working on Ghahari’s research team will create tiny graphene heterostructures on George Mason’s Fairfax Campus, and subsequently use nanofabrication equipment at a nearby project collaborator, the National Institute for Standards and Technology (NIST), to integrate the quantum nanodevices. Finally, they will use a low temperature cryostat located at Ghahari’s lab at George Mason to measure these devices at extremely low temperatures and high magnetic fields.

As part of this award, Ghahari will design an education plan to educate George Mason community on quantum nanoscience research by leveraging her unique expertise and established collaborations, which can enhance and expand the existing infrastructure.  This plan also includes promoting outreach and educational opportunities for students and underrepresented groups by offering seminars and additional quantum courses. She seeks to introduce quantum concepts to high school students to foster awareness and cultivate interest at an earlier age. According to Ghahari, mentorship plays an essential role in a student’s academic experience.

“Mentoring is crucial,” Ghahari said. “As a student, I often sought inspiration. Now, I strive to share my passion and interest in the subject as I work with students.”

With the NSF support, Ghahari’s study will receive $564,695 over the course of five years.