To make use of emerging molecular quantum hardware, we need to develop quantum algorithms and quantum software. What exactly can we do with such a quantum computer and how do we take advantage of its quantum nature? Fundamentally, it is still unclear how the inherent complexity of the entangled quantum system can be used to represent an exponentially hard problem.  Despite the allure of the original idea of Feynman—that quantum computers can provide the means for modeling other quantum systems, e.g., by replacing traditional quantum chemistry approaches developed for classical computers by an entirely new way to represent and solve the Schrödinger equation, we are far from having a clear road-map towards practical quantum chemistry implemented on quantum computers. What is the best way to approach this problem—should it be an exact mapping between the quantum system and the quantum hardware (quantum simulator) or should we use qubits to implement quantum gates and use them to implement general algorithms for solving the Schrödinger equation (universal quantum computing)? The power of both simulators and universal algorithms are limited by the number of coupled qubits, in addition to other critical factors such  gate fidelity and the required precision of the observable being measured. Hence, the problem of the resource scaling with respect to the system size remains a challenge. This suggests that brute-force quantum chemistry on quantum computers is unlikely to become a practical tool, that some coarse-graining of the full quantum problem will need to be invoked, and that classical computing will be required to support certain parts of the computation (hybrid quantum-classical computing). This lecture will focus on the algorithms for complexity-reducing techniques developed in the context of classical quantum chemistry and  analyze their potential utility in thee context of quantum computing.

Quantum chemistry for quantum computing or quantum computing for quantum chemistry?

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.