We present a Monte Carlo algorithm that allows efficient and unbiased sampling of polymer melts consisting of two chains of equal length that jointly visit all the sites of a cubic lattice  . Using this algorithm  , we show that in the limit of a large lattice the two chains phase separate , in contradiction with the ideal chain behaviour predicted by the Flory theorem .
We present a Monte Carlo algorithm that provides efficient and unbiased sampling of polymer melts consisting of two chains of equal length that jointly visit all the sites of a cubic lattice with rod geometry L x L x rL and non-periodic (hard wall) boundary conditions . Using this algorithm for chains of length up to 40 000 monomers and aspect ratios 1 <= r <= 10 , we show that in the limit of a large lattice the two chains phase separate . This demixing phenomenon is present already for r=1, and becomes more pronounced, albeit not perfect, as r is increased .
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allows
provides
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with rod geometry L x L x rL and non-periodic (hard wall) boundary conditions
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for chains of length up to 40 000 monomers and aspect ratios 1 <= r <= 10
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, in contradiction with the ideal chain behaviour predicted by the Flory theorem
. This demixing phenomenon is present already for r=1, and becomes more pronounced, albeit not perfect, as r is increased