Short-range entanglement and invertible field theories [article]

Daniel S. Freed
2014 arXiv   pre-print
Quantum field theories with an energy gap can be approximated at long-range by topological quantum field theories. The same should be true for suitable condensed matter systems. For those with short range entanglement (SRE) the effective topological theory is invertible, and so amenable to study via stable homotopy theory. This leads to concrete topological invariants of gapped SRE phases which are finer than existing invariants. Computations in examples demonstrate their effectiveness.
arXiv:1406.7278v2 fatcat:vehwbxgqkjccpklj6uhlk4yiw4