Randomly Compiled Quantum Simulation with Exponentially Reduced Circuit Depths
- URL: http://arxiv.org/abs/2411.04240v2
- Date: Sat, 25 Jan 2025 18:36:43 GMT
- Title: Randomly Compiled Quantum Simulation with Exponentially Reduced Circuit Depths
- Abstract summary: We develop qFLO, a higher order randomised algorithm for time-evolution.<n> Notably, it requires no ancillary qubits or additional control gates making it especially promising for near-term quantum devices.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The quantum stochastic drift protocol, also known as qDRIFT, has become a popular algorithm for implementing time-evolution of quantum systems using randomised compiling. In this work we develop qFLO, a higher order randomised algorithm for time-evolution. To estimate an observable expectation value at time $T$ to precision $\epsilon$, we show it is sufficient to use circuit depths of $O(T^2\log(1/\epsilon))$ -- an exponential improvement over standard qDRIFT requirements with respect to $\epsilon$. The protocol achieves this using $O(1/\epsilon^2)$ repeated runs of the standard qDRIFT protocol combined with classical post-processing in the form of Richardson extrapolation. Notably, it requires no ancillary qubits or additional control gates making it especially promising for near-term quantum devices. Furthermore, it is well-conditioned and inherits many desirable properties of randomly compiled simulation methods, including circuit depths that do not explicitly depend on the number of terms in the Hamiltonian.
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