Saturday 07 June 2025
A team of researchers has developed a novel approach to calculating Green’s functions on quantum computers, which could lead to significant advancements in our understanding of complex systems and materials.
Green’s functions are mathematical tools used to describe the behavior of particles and their interactions in condensed matter physics. They’re essential for modeling the properties of materials, such as superconductors or magnets, but traditional methods for calculating them are often computationally intensive and limited by the number of qubits available on current quantum computers.
The new approach, developed by a team of researchers from IBM and EPFL, uses a technique called simultaneous circuit perturbation (SCP) to estimate Green’s functions. SCP involves applying multiple random perturbations to a quantum circuit in parallel, rather than one at a time, which allows for more efficient calculation of the function.
The key innovation is that SCP can be used to calculate the entire Green’s function, rather than just estimating specific properties or correlations. This enables researchers to gain a deeper understanding of complex systems and materials, without being limited by the number of qubits available on their quantum computer.
The technique was tested on two different models: the Heisenberg model, which describes the behavior of magnets, and the Fermi-Hubbard model, which is used to study superconductors. In both cases, the SCP approach resulted in accurate calculations of the Green’s function, even when using a relatively small number of qubits.
The potential applications of this technique are vast. For example, it could be used to design new materials with specific properties, or to study complex phenomena such as quantum chaos. It could also enable more accurate simulations of quantum systems, which is essential for the development of practical quantum computers.
While there are still challenges to overcome before SCP can be widely adopted, this breakthrough has the potential to revolutionize our ability to understand and simulate complex quantum systems. As researchers continue to push the boundaries of what’s possible with quantum computing, it’s exciting to think about the new insights and discoveries that could emerge from this innovative approach.
The team’s findings have been published in a recent paper, and are available online for anyone interested in learning more about their technique. As the field of quantum computing continues to evolve, it will be fascinating to see how SCP is developed and applied in the future.
Cite this article: “Quantum Leap: New Approach Revolutionizes Calculation of Greens Functions”, The Science Archive, 2025.
Quantum Computing, Green’S Functions, Condensed Matter Physics, Superconductors, Magnets, Quantum Chaos, Materials Science, Ibm, Epfl, Scp, Perturbation Theory.
