3. Our goal is to calculate transfer matrix element between two neighboring grains e S(Q( );Q~( )), where ; = denote two parts of the manifold, and and in the o -diagonal terms we kept a term / ~2. We rst evaluate ~ integral in the Gaussian approximation near ~ = 0:
1 1 2g cosh2 y
2 sinh2 y 4.
4 sin y1 sinh y0 sin 2 (ei 3.
1 We here consider a topological superconductor as a thermal insulator, i.e. our usage of the term `insulator' encompasses both conventional insulators, and superconductors.
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4 As a matter of principle, the momentum space description can be maintained at the expense of extending the unit cell from atomistic scales, a, to the system size, L (a disordered system is periodic in its own size.) However, the price to be payed is that the topological information is now encoded in the con guration dependent structure of O((L=a)d) bands. While the multi-band framework may still be accessible by numerical means, it is less suited for analytical theory building.
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