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arXiv · 1708.08443

Temporal order in periodically driven spins in star-shaped clusters

Soham Pal·Naveen Nishad·T S Mahesh·G J Sreejith
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Abstract

We experimentally study the response of star-shaped clusters of initially unentangled $N=4$, 10 and 37 nuclear spin-$\frac{1}{2}$ moments to an inexact $\pi$-pulse sequence, and show that an Ising coupling between the centre and the satellite spins results in robust period-two magnetization oscillations. The period is stable against bath-effects but the amplitude decays with a time scale that depends on the inexactness of the pulse. Simulations reveal a semiclassical picture where the rigidity of the period is due to a randomizing effect of the Larmor precession under the magnetization of surrounding spins. The time scales with stable periodicity increase with net initial magnetization even in the presence of perturbations, indicating a robust temporal ordered phase for large systems with finite magnetization per spin.

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Soham Pal, Naveen Nishad, T S Mahesh, G J Sreejith. 2017-08-28. Temporal order in periodically driven spins in star-shaped clusters. https://doi.org/10.1103/physrevlett.120.180602

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