摘要
Phonons,the quantized vibrations of atoms in solids,usually follow the Debye law:the vibrational density of states grows as the square of the vibration frequency.Yet real materials often deviate from this simple picture.Crystals exhibit sharp van Hove singularities(VHS),while glasses show the smoother but puzzling boson peak(BP).For decades these anomalies were studied separately.A key question has remained:could they share a universal origin?
