Collective tunneling of a Wigner necklace in carbon nanotubes

The collective tunneling of a Wigner necklace - a crystal-like state of a small number of strongly interacting electrons confined to a suspended nanotube and subject to a double-well potential - is theoretically analyzed and compared with experiments in Shapir et al. [Science 364, 870 (2019)0036-807510.1126/science.aat0905]. Density matrix renormalization group computations, exact diagonalization, and instanton theory provide a consistent description of this very strongly interacting system, and show good agreement with experiments. Experimentally extracted and theoretically computed tunneling amplitudes exhibit a scaling collapse. Collective quantum fluctuations renormalize the tunneling, and substantially enhance it as the number of electrons increases.