Modeling and simulation of a quantum thermal noise on the qubit

TL;DR

This paper develops a circuit model to simulate thermal noise on qubits, enabling better understanding and testing of quantum systems affected by thermal decoherence, and demonstrates its implementation on IBM-Q hardware.

Contribution

The paper introduces a novel circuit model for simulating thermal noise on qubits using elementary operators, facilitating practical noise analysis in quantum computing.

Findings

Successfully derived a dilated unitary model for thermal noise

Implemented the noise simulator on IBM-Q hardware

Provides a controllable and integrable tool for thermal noise simulation

Abstract

Quantum noise or decoherence is a major factor impacting the performance of quantum technologies. On the qubit, an important quantum noise, often relevant in practice, is the thermal noise or generalized amplitude damping noise, describing the interaction with a thermal bath at an arbitrary temperature. A qubit thermal noise however cannot be modeled nor directly simulated with a few elementary Pauli operators, but instead requires specific operators. Our main goal here is to construct a circuit model for simulating the thermal noise from standard elementary qubit operators. Starting from a common quantum-operation model based on Kraus operators and an associated qubit-environment model, we derive a proper Stinespring dilated representation for the thermal noise. This dilated unitary model is then decomposed in terms of simple elementary qubit operators, and converted into a circuit based on elementary quantum gates. We arrive at our targeted simulator circuit for the thermal noise, coming with built-in easy control on the noise parameters. The noise simulator is then physically implemented and tested on an IBM-Q quantum processor. The simulator represents a useful addition to existing libraries of quantum circuits for quantum processors, and it offers a new tool for investigating quantum signal and information processing having to cope with thermal noise.