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arXiv · 1801.04594

Quantum spin circulator in Y junctions of Heisenberg chains

F. Buccheri·R. Egger·R. G. Pereira·F. B. Ramos
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Abstract

We show that a quantum spin circulator, a nonreciprocal device that routes spin currents without any charge transport, can be achieved in Y junctions of identical spin-$1/2$ Heisenberg chains coupled by a chiral three-spin interaction. Using bosonization, boundary conformal field theory, and density-matrix renormalization group simulations, we find that a chiral fixed point with maximally asymmetric spin conductance arises at a critical point separating a regime of disconnected chains from a spin-only version of the three-channel Kondo effect. We argue that networks of spin-chain Y junctions provide a controllable approach to construct long-sought chiral spin liquid phases.

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F. Buccheri, R. Egger, R. G. Pereira, F. B. Ramos. 2018-01-14. Quantum spin circulator in Y junctions of Heisenberg chains. https://doi.org/10.1103/physrevb.97.220402

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