Polynomial-time quantum algorithm for the simulation of chemical dynamics.

Area of Science:

• Quantum computing
• Computational chemistry
• Quantum simulation

Background:

• Classical computational cost for exact quantum simulation grows exponentially with system size, limiting applications to small systems.
• The Born-Oppenheimer approximation is a standard but sometimes inaccurate simplification in computational chemistry.

Purpose of the Study:

• To demonstrate that quantum computers can simulate chemical reactions exactly in polynomial time.
• To develop an efficient quantum algorithm for chemical reaction simulation.
• To enable accurate and efficient calculation of chemical reaction rates and properties.

Main Methods:

• Utilizing the split-operator approach for quantum simulation.
• Explicitly simulating all electron-nuclear and interelectronic interactions.
• Propagating the entire electronic wave function on a grid.
• Developing efficient methods for state preparation and observable measurement on quantum computers.

Main Results:

• Quantum computers can simulate chemical reactions exactly in quadratic time.
• The quantum approach is more accurate, faster, and efficient than the Born-Oppenheimer approximation for systems with more than four atoms.
• Efficient preparation of chemically relevant states and measurement of observables like transition probabilities and reaction rates are demonstrated.
• Quantum computers with approximately 100 qubits could outperform current classical computers.

Conclusions:

• Quantum computing offers a powerful and efficient alternative for exact quantum simulation of chemical reactions.
• The developed quantum algorithm overcomes limitations of classical methods and approximations.
• This work paves the way for accurate and efficient quantum chemical calculations on near-term quantum devices.