Spin versus charge noise from Kondo traps
arXiv:1503.08741 · doi:10.1103/PhysRevB.92.085123
Abstract
Magnetic and charge noise have common microscopic origin in solid state devices, as described by a universal electron trap model. In spite of this common origin, magnetic (spin) and charge noise spectral densities display remarkably different behaviours when many-particle correlations are taken into account, leading to the emergence of the Kondo effect. Our numerical renormalization group results indicate that while spin noise is a universal function of the Kondo temperature, charge noise remains well described by single-particle theory even when the trap is deep in the Kondo regime. This difference survives even in the presence of disorder, showing that noise can be more manageable in devices that are sensitive to magnetic (rather than charge) fluctuations and that the signature of the Kondo effect can be observed in spin noise spectroscopy experiments.
9 pages, 6 figures; To appear in PRB. Revised version: includes derivation of exact sum rules, analytical approximation for the spin noise, and additional details of the NRG calculation
References in corpus (13)
- The numerical renormalization group method for quantum impurity systems
- Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
- A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
- Magnetism in SQUIDs at Millikelvin Temperatures
- Microscopic origin of low frequency flux noise in Josephson circuits
- Dangling-bond spin relaxation and magnetic 1/f noise from the amorphous-semiconductor/oxide interface: Theory
- Kondo physics and dissipation: A numerical renormalization-group approach to Bose-Fermi Kondo models
- Non-equilibrium frequency-dependent noise through a quantum dot: A real time functional renormalization group approach
- Microscopic model of critical current noise in Josephson-junction qubits: Subgap resonances and Andreev bound states
- Ohmic and step noise from a single trapping center hybridized with a Fermi sea
- Finite-frequency-dependent noise of a quantum dot in a magnetic field
- Transport properties of fully screened Kondo models
- Spin and orbital fluctuations in non-equilibrium transport through quantum dots: A renormalisation-group analysis