Influence of Random Telegraph Noise on Quantum Bit Gate Operation

TL;DR

This paper analyzes how Random Telegraph Noise affects spin-flip qubit gate operations using composite pulses, identifying optimal sequences and conditions that maintain high fidelity despite noise, which is crucial for quantum error correction.

Contribution

It introduces a detailed analysis of pulse sequences in the presence of RTN, proposing optimal strategies for high-fidelity qubit gates under noisy conditions.

Findings

High fidelity (>90%) achieved despite RTN effects.

Optimal pulse sequences depend on RTN jump speed.

Specific pulse directions improve robustness against noise.

Abstract

We consider the problem of analyzing spin-flip qubit gate operation in presence of Random Telegraph Noise (RTN). Our broad approach is the following. We calculate the spin-flip probability of qubit driven by composite pulses, (Constant pulse (C-pulse), Quantum Well pulse (QW-pulse) and Barrier Potential pulse (BP-pulse)) in the presence of RTN using Feynman disentangling method. When composite pulses and RTN act in x-direction and z-direction respectively, we calculate the optimal time to achieve 100% spin-flip probability of qubit. We report the shortcut of spin-flip qubit, which can be achieved by using C-pulse, followed by BP-pulse and QW-pulse. When jumps time in RTN are very fast, tuning of perfect fidelity or spin-flip probability extends to large RTN correlation time. On the other hand, when the jumps in RTN are very slow, the BP-pulse can be used to recover the lost fidelities. Nevertheless, the fidelities of qubit gate operation are larger than 90%, regardless of RTN jumps environments which may be beneficial in quantum error correction. For more general case, we have tested several pulse sequences for achieving high fidelity quantum gates, where we have used the pulses acting in different directions. From the calculations, we find high fidelity of qubit gate operation in presence of RTN is achieved when QW-pulse, BP-pulse and C-pulse act in x-direction, y-direction and z-direction, respectively.