Dangling-bond spin relaxation and magnetic 1/f noise from the amorphous-semiconductor/oxide interface: Theory
| dc.creator | de Sousa, Rogerio | |
| dc.date | 2007-05-28 | |
| dc.date | 2008-01-19 | |
| dc.date.accessioned | 2026-07-07T08:55:06Z | |
| dc.date.available | 2026-07-07T08:55:06Z | |
| dc.description | We propose a model for magnetic noise based on spin-flips (not electron-trapping) of paramagnetic dangling-bonds at the amorphous-semiconductor/oxide interface. A wide distribution of spin-flip times is derived from the single-phonon cross-relaxation mechanism for a dangling-bond interacting with the tunneling two-level systems of the amorphous interface. The temperature and frequency dependence is sensitive to three energy scales: The dangling-bond spin Zeeman energy delta, as well as the minimum (E_min) and maximum (E_max) values for the energy splittings of the tunneling two-level systems. We compare and fit our model parameters to a recent experiment probing spin coherence of antimony donors implanted in nuclear-spin-free silicon [T. Schenkel {\it et al.}, Appl. Phys. Lett. 88, 112101 (2006)], and conclude that a dangling-bond area density of the order of 10^{14}cm^{-2} is consistent with the data. This enables the prediction of single spin qubit coherence times as a function of the distance from the interface and the dangling-bond area density in a real device structure. We apply our theory to calculations of magnetic flux noise affecting SQUID devices due to their Si/SiO_2 substrate. Our explicit estimates of flux noise in SQUIDs lead to a noise spectral density of the order of 10^{-12}Phi_{0}^{2} {Hz}^{-1} at f=1Hz. This value might explain the origin of flux noise in some SQUID devices. Finally, we consider the suppression of these effects using surface passivation with hydrogen, and the residual nuclear-spin noise resulting from a perfect silicon-hydride surface. | |
| dc.description | Final published version | |
| dc.identifier | https://arxiv.org/abs/0705.4088 | |
| dc.identifier | http://arxiv.org/abs/0705.4088 | |
| dc.identifier | Phys. Rev. B 76, 245306 (2007) | |
| dc.identifier | doi:10.1103/PhysRevB.76.245306 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/146169 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.subject | Materials Science | |
| dc.title | Dangling-bond spin relaxation and magnetic 1/f noise from the amorphous-semiconductor/oxide interface: Theory | |
| dc.type | text |