EAGER: QAC: QCH: Holographic Quantum Algorithms for Simulating Many-Body Systems

University Of Texas At Austin, Austin TX

Investigators

Abstract

Nontechnical Summary Accurately modeling materials is essential for guiding materials discovery and designing advanced electronic devices. However, simulating the quantum-mechanical properties of materials on a microscopic scale poses tremendous computational challenges that often exceed the capabilities of even the most advanced supercomputers. Quantum computers offer a potential means to circumvent these challenges by harnessing the same aspects of quantum physics that make material simulation challenging for conventional computers. While a promising approach, there is a large gap in size and accuracy between quantum computers that can be built with current technology and those needed to make progress on real-world relevant materials challenges. To close this gap, this project will develop quantum software and hardware prototypes in which quantum computations are performed on efficiently compressed quantum data, to dramatically reduce the resources required to simulate large-scale material models. These techniques are dubbed “holographic” as they encode high-dimensional data on a lower-dimensional physical system, much like a hologram. This research will expedite the application of near-term quantum computers, with limited memory and accuracy, to realistic materials and chemical modeling. Technical summary This project will develop holographic quantum simulation techniques that indirectly encode the quantum state of a material in an efficiently compressed representation that greatly reduces the number of required qubits, and fundamentally limits the impact of noise and errors. This compression is achieved by an algorithm that alternates between coherent entangling gates and measurement of a selected subset of qubits. This approach represents a dramatic departure from conventional quantum algorithmic frameworks and will require a fundamental rethinking of quantum algorithm and hardware design. This project will conduct research to establish a basic theoretical and experimental proof-of-principle for holographic simulation techniques. Advanced holographic simulation techniques will be developed to treat electronic materials, 2d and 3d models, and compute non-equilibrium electronic and thermal transport and optical spectra relevant for real-world devices. The fundamental capabilities and limitations of holographic representations of quantum states will be rigorously characterized. The project team will fabricate a circuit quantum electrodynamics (cQED) testbed in which a two-level superconducting qubit controls a multi-level superconducting cavity mode. The multi-level cavity mode provides a larger quantum memory than a conventional two-level qubit, and the hybrid qubit/cavity system provides powerful methods to create quantum entanglement. Together, these advantages will enable simulation of more complex material states with the same number of quantum devices compared to conventional qubit-only systems. The project team will demonstrate the developed holographic algorithms on this cQED testbed and benchmark its performance against complementary simulations on commercial quantum computing platforms. Lessons learned from this exploratory phase will be used to design scalable cQED devices for holographic simulations of large-scale problems that exceed the capabilities of current classical supercomputers. This EAGER award by the Division of Materials Research is jointly supported with the Division of Chemistry. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.