Flux $1/f^{\alpha }$ noise in 2D Heisenberg spin glasses: effects of weak anisotropic interactions

Abstract

We study the dynamics of a two-dimensional ensemble of randomly distributed classical Heisenberg spins with isotropic RKKY and weaker anisotropic dipole-dipole couplings. Such ensembles may give rise to the flux noise observed in SQUIDs with a $1/f^{\alpha }$ power spectrum ($\alpha \lesssim 1$). We solve numerically the Landau-Lifshiftz-Gilbert equations of motion in the dissipationless limit. We find that Ising type fluctuators, which arise from spin clustering close to a spin-glass critical behavior with $T_c=0$, give rise to $1/f^{\alpha }$ noise. Even weak anisotropic interactions lead to a crossover from the Heisenberg-type criticality to the much stronger Ising-type criticality. The temperature dependent exponent $\alpha (T)\lesssim 1$ grows and approaches unity when the temperature is lowered. This mechanism acts in parallel to the spin diffusion mechanism. Whereas the latter is sensitive to the device geometry, the spin-clustering mechanism is largely geometry independent.

7 pages

References in corpus (13)

• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• 1/f noise: implications for solid-state quantum information
• Decoherence of flux qubits due to 1/f flux noise
• Model for l/f Flux Noise in SQUIDs and Qubits
• 1/f Flux Noise in Josephson Phase Qubits
• Dephasing of a superconducting flux qubit
• Magnetism in SQUIDs at Millikelvin Temperatures
• Microscopic origin of low frequency flux noise in Josephson circuits
• Measurement-induced qubit state mixing in circuit QED from up-converted dephasing noise
• Probing Noise in Flux Qubits via Macroscopic Resonant Tunneling
• Spin-like susceptibility of metallic and insulating thin films at low temperature
• Evidence for temperature dependent spin-diffusion as a mechanism of intrinsic flux noise in SQUIDs
• Effect of exchange interaction on the spin fluctuations of localized electrons

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• Evolution of $1/f$ Flux Noise in Superconducting Qubits with Weak Magnetic Fields
• $1/f^{\alpha }$ noise and generalized diffusion in random Heisenberg spin systems
• Flux-vector model of spin noise in superconducting circuits: Electron versus nuclear spins and role of phase transition
• Nonequilibrium Spin Noise and Noise of Susceptibility
• An Ising-Glauber Spin Cluster Model for Temperature Dependent Magnetization Noise in SQUIDs
• Lasing in circuit quantum electrodynamics with strong noise
• Spiral Spin Liquid Noise
• Kubo spins in nano-scale aluminum grains: A muon spin relaxation study
• Loss and decoherence in superconducting circuits on silicon: Insights from electron spin resonance
• Flux noise in disordered spin systems