Speaker
Description
Imaginary-time evolution (ITE) provides a direct route to ground-state preparation by exponentially suppressing excited-state contributions, but practical implementations on quantum hardware are limited by rapidly growing circuit depth and intrinsically low per-step success probabilities. To address these limitations, we develop a variational imaginary-time evolution framework based on polynomial filtering, derived from an operator-level action principle, which yields an optimized non-unitary projector expressed as a finite polynomial in the Hamiltonian. Starting from a single-ancilla, first-order imaginary-time update defined by a Taylor expansion, we show that replacing the Taylor form with a variational polynomial substantially improves both accuracy and stability at larger time steps, leading to up to an order-of-magnitude enhancement in the final success probability. Benchmarks on the transverse-field Ising model demonstrate faster convergence to the ground-state energy and improved robustness compared to standard Taylor-based ITE, highlighting variational polynomial filtering as a practical route to higher-fidelity ground-state preparation on near-term quantum devices.
| Keyword-1 | Imaginary-Time Evolution |
|---|---|
| Keyword-2 | Quantum Circuits |
| Keyword-3 | Ancilla-Based ITE |