# Suppression of 1/f noise in one-qubit systems

## TL;DR

This paper develops a method to model 1/f^\alpha noise in one-qubit systems using a discrete Markovian fluctuator, enabling high-fidelity quantum operations like memory and gates through optimization.

## Contribution

It introduces an efficient approximation of 1/f^\alpha noise with a Markovian model and applies deterministic master equations for high-fidelity quantum control.

## Key findings

- High-fidelity quantum gates achieved under 1/f^\alpha noise
- Fidelity for NOT gate similar to random telegraph noise
- Memory fidelity shows nonmonotonic dependence on operation time

## Abstract

We investigate the generation of quantum operations for one-qubit systems under classical noise with 1/f^\alpha power spectrum, where 2>\alpha > 0. We present an efficient way to approximate the noise with a discrete multi-state Markovian fluctuator. With this method, the average temporal evolution of the qubit density matrix under 1/f^\alpha noise can be feasibly determined from recently derived deterministic master equations. We obtain qubit operations such as quantum memory and the NOT}gate to high fidelity by a gradient based optimization algorithm. For the NOT gate, the computed fidelities are qualitatively similar to those obtained earlier for random telegraph noise. In the case of quantum memory however, we observe a nonmonotonic dependency of the fidelity on the operation time, yielding a natural access rate of the memory.