Functional Nanomaterials

Using nanoscale devices to study material properties on nanoscale

Nanomechanical measurement of spin dynamics can be done by detecting the corresponding change in angular momentum or torque. This minimally-invasive approach enables measurement and manipulation of spin states in magnetic materials, and protected spin states in topological insulators relevant for quantum computing applications. Using a nanomechanical torsion oscillator, we have demonstrated one of the most sensitive measurements of torque with a magnitude comparable to that of a unwinding DNA.

Coupling of nonlinear polarization in a dielectric medium in a piezoelectric film to mechanical motion leads to a resonator with nonlinear behavior in the acoustic frequency range. We have transduced nonlinear behavior in a dielectric medium into a range of mechanical effects—including second harmonic generation.

Other studies of nanomaterials include superconductivity in boron-doped diamond, nonlinear dissipation in silicon resonators, and piezoelectricity in aluminum nitride.

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Dielectric nonlinearity: Nonlinear-optics effects in a micromechanical resonator:

Coupling of nonlinear polarization in a dielectric medium in a piezoelectric film to mechanical motion leads to a resonator with nonlinear behavior in the acoustic frequency range.

Spin Mechanics

Spin is an intrinsically quantum property, characterizing angular momentum. A change in the electron spin state is equivalent to a change in the angular momentum or mechanical torque. Could this torque be measured by nanomechanical torsion resonator?

Diamonds Are Forever

Diamond is amazing. It is an extremely hard material with high fracture constant and high elastic modulus. It conducts heat better than gold, copper and silicon. Naturally occurring diamond is an electrical insulator, however with suitable doping it can be easily transformed into a semiconductor or even a conventional superconductor with relatively high critical temperature.

Nonlinear Dissipation in Nanomechanics

Dissipation of energy in micro- and nano-electromechanical resonators governs their dynamical response and limits their potential use in device applications. Quantified by the quality factor Q, dissipation (1/Q) usually occurs by energy loss mechanisms that are linear, appearing as a damping term proportional to the velocity.

Dissipation in Nanoelectromechanical Systems (Review)

This article is a review of the dissipation processes in nanoelectromechanical systems (NEMS).

Energy measurement in nonlinearly coupled nanomechanical modes.

We report direct measurements of average vibration energy in a high frequency flexural resonance mode achieved via an-harmonic elastic coupling to a fundamental vibration mode of a nanomechanical resonator.