Mechanical sources of dissipation play a key role in
modern physics, with applications that span nanomechanics,
biomechanics, materials science, and quantum computing. In clocks
and other vibrating mechanisms, energy loss is usually proportional
to the speed of the vibrating object. But in special circumstances,
where one resonant frequency of the resonator is exactly twice as
high as another resonant frequency, these losses suddenly become
much greater, as additional energy is lost through the coupling
between these modes of vibration. With support from the European
Research Council (ERC), associate professor Farbod Alijani and Ata
Keşkekler Ph.D. student in the department of precision and
microsystems engineering at TU Delft, tuned the interaction between
the vibrational states of a graphene nanodrum in such a way that
one mode vibrates exactly twice as fast as another. In doing so,
they also showed that with this mechanism it is possible to control
the damping force via the coupling strength between the two
vibration modes.
Researchers clarify the microscopic origin of dissipation
with graphene
