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arXiv · 0809.0038

Path integral study of the role of correlation in exchange coupling of spins in double quantum dots and optical lattices

Lei Zhang·Matthew Gilbert·Jesper Pedersen·John Shumway
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Abstract

We explore exchange coupling of a pair of spins in a double dot and in an optical lattice. Our algorithm uses the frequency of exchanges in a bosonic path integral, evaluated with Monte Carlo. This algorithm is simple enough to be a "black box" calculator, yet gives insights into the role of correlation through two-particle probability densities, visualization of instantons, and pair correlation functions. We map the problem to Hubbard model and see that exchange and correlation renormalize the effective parameters, dramatically lowering U at larger separations.

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Lei Zhang, Matthew Gilbert, Jesper Pedersen, John Shumway. 2008-08-30. Path integral study of the role of correlation in exchange coupling of spins in double quantum dots and optical lattices. https://doi.org/10.1088/0953-8984%2F22%2F14%2F145301

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