Tunneling Defect Nanoclusters in hcp 4He Crystals: Alternative to Supersolidity

A?simple model based on the concept of resonant tunneling clusters of lattice defects is used to explain the low temperature anomalies of hcp ⁴He crystals (mass decoupling from a torsional oscillator, shear modulus anomaly, dissipation peaks, heat capacity peak). Mass decoupling is a result of an internal Josephson effect: mass supercurrent inside phase coherent tunneling clusters. Quantitative results are in reasonable agreement with experiments.