qrunch.quantum.circuits.hamiltonian_time_evolution.qdrift

The qDRIFT randomized compiler for Hamiltonian time evolution.

Classes

QDrift

qDRIFT randomized compiler for Hamiltonian time evolution.
class QDrift

Bases: HamiltonianTimeEvolution

qDRIFT randomized compiler for Hamiltonian time evolution.

Approximates \(e^{-iHt}\) by an ensemble of circuits, where each gate is a randomly sampled Hermitian term of the Hamiltonian, sampled with probability proportional to the absolute value of its coefficient.

__init__(subsequence_length: int, seed: int | None = None) → None

Initialize the qDRIFT compiler.

Parameters:

  • subsequence_length (int) – The length of the subsequences used in the qDRIFT compilation.

  • seed (int | None) – Optional seed for the random term sampling.

Return type:

None

get_circuit(hamiltonian: SecondQuantizedHamiltonian, time: float) → Circuit

Build a qDRIFT circuit approximating the time evolution of the given Hamiltonian.

Parameters:

  • hamiltonian (SecondQuantizedHamiltonian) – The second-quantized Hamiltonian to time-evolve.

  • time (float) – The evolution time.

Return type:

Circuit