Tunneling states and localized mode in binary bulk metallic glass

The low-temperature specific heat of Cu₅₀Zr₅₀ binary bulk metallic glass is systemically measured from 1.80.3em0exK0.3em0exto0.3em0ex50.50.3em0exK. The obvious effect of the tunneling states is determined at several Kelvin by both specific heat and electrical resistivity. The density of the electron-assisted tunneling states in the bulk metallic glass at several Kelvin exceed the typical value in insulating glasses below 10.3em0exK by 2--3 orders of magnitude, and the entropy of the tunneling states is about 7.850.3em0exmJ∕mol0.2em0exK. The specific heat in the wide temperature range was analyzed by the conventional Debye and Einstein models, and the results demonstrate the existence of the localized mode which is correlated to the boson peak in the metallic glass.