Professors Angela Kou, Pinshane Huang, Wolfgang Pfaff, and Andre Schleife from the University of Illinois Urbana-Champaign have received a nearly $1 million grant from the Air Force Office of Scientific Research. The funding is for a project to identify and address defects in Josephson junctions, a key component in superconducting qubits used in quantum computing. The team will use transmission electron microscopy to study the defects and losses in the junctions. The goal is to improve the control and predictability of these junctions, which could help advance the field of quantum computing.
Quantum Computing Research at the University of Illinois Urbana-Champaign
Quantum computing is currently in what is known as the noisy intermediate-scale quantum device era. In this stage, the number of qubits, or quantum processing units, and junctions per chip is increasing, but control over these elements is not yet refined enough to build a fully functioning quantum computer. One of the main challenges in quantum information research is figuring out how to build efficient qubits and hardware for quantum information processing.
Superconducting Qubits and Josephson Junctions
Superconducting qubits are a popular platform in quantum computing research, with companies like IBM and Rigetti creating qubits that use superconducting properties. These qubits use superconducting materials where the circuits are based on aluminum/aluminum oxide/aluminum junctions, known as Josephson junctions. These junctions need to be controlled at a very high level so that their behaviour can be predicted when incorporated into quantum hardware. However, the junctions are made via a metal evaporation process and the microscopic details of the junction are not well-controlled, leading to a lot of disorder in the material and making it difficult to predict the behaviour of the material.
The Research Project and Its Goals
The grant awarded to the team at the University of Illinois Urbana-Champaign is aimed at understanding and controlling these aluminum oxide junctions. The team plans to study the defects and losses in the junctions using two main approaches. The first is structural characterisation, using transmission electron microscopy (TEM) to examine the morphology and structure of the junctions and to determine the concentrations of aluminum and oxygen and the level of disorder in the oxide. The second approach is characterisation of the devices at low temperatures to determine the density of defects in the junction.
Collaboration and Future Prospects
The project is a collaboration between the materials science and engineering department and the physics department at the University of Illinois Urbana-Champaign. The team hopes that the data from their research will provide a comprehensive understanding of Josephson junctions and help to reduce the number of detrimental defects in these devices, thereby advancing the field of quantum computing.
“This grant is looking at how to control these aluminum oxide junctions and to understand the materials science behind the junctions a bit more, and then ultimately see if we can make better junctions,” says project lead Kou.
Kou says “it’s possible that we can make something better with one device, but it’s not something generalizable. I’m really excited to be able to create a full picture of a Josephson junction. If we could have a recipe for figuring out how to reduce the number of detrimental defects that couple to our devices, that would help push the field forward.”
Kou highlights the collaboration between the materials science and engineering department and the physics department, “it is special that it’s easy for us to find a TEM expert or dynamic modeling expert just down the hall and makes a grant like this possible.”
Summary
Professors from the University of Illinois Urbana-Champaign have secured a nearly $1 million grant to investigate and address defects in Josephson junctions, a key component in superconducting qubits used in quantum computing. The research aims to improve the control and predictability of these junctions, potentially advancing the field of quantum information research.
- Professors Angela Kou, Pinshane Huang, Wolfgang Pfaff, and Andre Schleife from the University of Illinois Urbana-Champaign have received a nearly $1 million grant from the Air Force Office of Scientific Research.
- The grant is for a project focused on identifying and addressing defects in Josephson junctions, a key component in superconducting qubits used in quantum computing.
- The current stage of quantum computing, known as the noisy intermediate-scale quantum device era, is characterised by an increasing but uncontrolled number of qubits and junctions per chip.
- The team will use two main approaches to study the defects and losses in the junctions: structural characterisation using transmission electron microscopy (TEM), and low-temperature device characterisation to determine defect density.
- The data collected will be used to generate statistics and potentially create a ‘recipe’ for reducing the number of detrimental defects in the junctions, which could advance the field of quantum computing.
- The project highlights the collaborative efforts between the materials science and engineering department and the physics department at the university.
