Statistical Phase Estimation
In this tutorial, we will go over how to execute statistical phase estimation (SPE) using QURI Algo and QURI VM.
Overview
SPE is an algorithm that is used to estimate the eigenenergies of a problem Hamiltonian. It does so by performing a Hadamard test on a trial wave-function, resulting in a measurable signal that can be used to infer the wave-functions spectral density. If this wave-function has a significant overlap with the true ground state of the system, the ground state energy should make a significant contribution to the spectral density. The following propoerties makes SPE an attractive algorithm in EFTQC
- Good circuit depth scaling compared to FTQC algorithms
- The run-time scales with the energy accuracy as
- Noise resilience
In this notebook we will introduce all of the pieces needed to run SPE. In order, this notebook will
- Explain the LT22 and Gaussian filter variants of SPE and showcase their implementations in QURI Algo
- Instruct in the use of QURI Parts' noise models and showcase the robustness of SPE to noise based on the STAR architecture
- Estimate the Fidelity of the Hadamard test circuits used in SPE after transpilation to the STAR architecture and introduce QURI VM.