Evanescent-wave Johnson Noise in small devices

Abstract

In many quantum computer architectures, the qubits are in close proximity to metallic device elements. The fluctuating currents in the metal give rise to noisy electromagnetic fields that leak out into the surrounding region. These fields are known as evanescent-wave Johnson noise. The noise can decohere the qubits. We present the general theory of this effect for charge qubits subject to electric noise and for spin and magnetic qubits subject to magnetic noise. A mapping of the quantum-mechanical problem onto a problem in classical electrodynamics simplifies the calculations. The focus is on relatively simple geometries in which analytical calculations can be done. New results are presented for the local noise spectral density in the vicinity of cylindrical conductors such as small antennae, noise from objects that can be treated as dipoles, and noise correlation functions for several geometries. We summarize the current state of the comparison of theory with experimental results on decoherence times of qubits. Emphasis is placed on qualitative understanding of the basic concepts and phenomena.

arXiv comment36 pages, 8 figures

References in corpus (25)

• Quantum state engineering with Josephson-junction devices
• Single-shot read-out of an individual electron spin in a quantum dot
• Surface Electromagnetic Waves Thermally Excited: Radiative Heat Transfer, Coherence Properties and Casimir Forces Revisited in the Near Field
• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Coherent manipulation of electronic states in a double quantum dot
• Storing quantum information for 30 seconds in a nanoelectronic device
• Manipulation of a single charge in a double quantum dot
• Charge-qubit operation of an isolated double quantum dot
• Atom Chips
• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Adiabatic quantum computation with Cooper pairs
• Electrical control of spin relaxation in a quantum dot
• Loss and heating of particles in small and noisy traps
• Measurement of the Spin Relaxation Time of Single Electrons in a Silicon MOS-Based Quantum Dot
• Qubits with electrons on liquid helium
• Heating of trapped atoms near thermal surfaces
• Spin Relaxation due to Charge Noise
• Qubit relaxation from evanescent-wave Johnson noise
• Do micromagnets expose spin qubits to charge and Johnson noise?
• Impact of g-factors and valleys on spin qubits in a silicon double quantum dot
• A simple quantum gate with atom chips
• Relaxation in quantum dots due to evanescent-wave Johnson noise from a metallic backgate
• Electromagnetic properties of thin metallic films
• Decoherence by electromagnetic fluctuations in double-quantum-dot charge qubits
• Thermally Induced Losses in Ultra-Cold Atoms Magnetically Trapped Near Room-Temperature Surfaces

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• Computational Electromagnetics Meets Spin Qubits: Controlling Noise Effects in Quantum Sensing and Computing
• Nanophotonic Super-dephasing in Collective Atom-Atom Interactions
• Magnetic Noise from Metal Objects near Qubit Arrays
• Electrostatic transfer of sub-micron magnetic particles onto cantilevers using a focused ion beam system