Dynamics of large anisotropic spin in a sub-ohmic dissipative environment close to a quantum-phase transition - Condensed Matter > Mesoscale and Nanoscale PhysicsReport as inadecuate




Dynamics of large anisotropic spin in a sub-ohmic dissipative environment close to a quantum-phase transition - Condensed Matter > Mesoscale and Nanoscale Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We investigate the dynamics of a large anisotropic spin whose easy-axiscomponent is coupled to a bosonic bath with a spectral function $J\w\propto\omega^s$. Such a spin complex might be realized in a single-molecular magnet.Using the non-perturbative renormalization group, we calculate the line ofquantum-phase transitions in the sub-ohmic regime $s<1$. These quantum-phasetransitions only occur for integer spin $J$. For half-integer $J$, the lowtemperature fixed-point is identical to the fixed-point of the spin-boson modelwithout quantum-tunneling between the two levels. Short-time coherentoscillations in the spin decay prevail even into the localized phase in thesub-ohmic regime. The influence of the reorganization energy and the recurrencetime on the decoherence in the absence of quantum-tunneling is discussed.



Author: Frithjof B. Anders

Source: https://arxiv.org/







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