Quantum Computation of Electronic Structure with Projector Augmented-Wave Method and Plane Wave Basis Set.

Area of Science:

• Quantum computing applications in materials science.
• Development of novel quantum algorithms for electronic structure calculations.

Background:

• Quantum simulation promises accurate materials modeling but requires significant quantum resources.
• Classical methods like Projector Augmented-Wave (PAW) reduce computational cost but are incompatible with quantum computing due to non-orthogonality.
• Accurate quantum simulations need efficient algorithms that minimize qubit and gate requirements.

Purpose of the Study:

• To develop a quantum-compatible version of the PAW method for efficient materials simulation.
• To enable accurate ground state energy estimation using reduced quantum resources.
• To apply the developed method to challenging systems like point defects in solids.

Main Methods:

• Developed a Unitary Projector Augmented-Wave (UPAW) method preserving orthogonality constraints.
• Utilized linear-combination-of-unitaries decomposition for Hamiltonian representation.
• Employed qubitized quantum phase estimation for ground state energy estimation.
• Extended classical down-sampling techniques to the quantum setting for algorithmic efficiency.

Main Results:

• Demonstrated the feasibility of UPAW for quantum electronic structure calculations.
• Estimated quantum resources for crystalline solids achieving chemical accuracy.
• Applied a supercell approach for defect state calculations, including a nitrogen-vacancy center in diamond.
• Showcased resource estimates for a challenging quantum point defect system.

Conclusions:

• The UPAW method offers a resource-efficient and accurate approach for quantum materials simulation.
• This work paves the way for tackling complex problems in condensed matter physics and quantum chemistry.
• The developed techniques are crucial for advancing the practical application of quantum computers in materials science.