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Quantization of mechanical energy: gigahertz modes, ultra low temperatures, novel nonlinear energy measurement scheme.

The most exciting quantum effect in a resonator is quantization of energy in terms of quantized phonons.  As temperature is reduced, the occupation number of phonons in the resonator mode is reduced, going from a classically large number to a small (quantized) number, where the discreteness can be probed by available techniques. Not only is the observation quantization of phonons exciting, it can also lead to the study of even more tantalizing phenomena such as phonon bunching and other quantum statistical effects observed in boson systems. If observed, these phenomena will have far-reaching consequences in both fundamental and applied sciences.

    Using techniques developed in our group in the last four years. We are currently working on a number of experiments to observe energy trapping in modes of micromechanical resonators, and emission and absorption of quantized phonons at low temperatures, phonon bunching and other non-classical effects.


A scanning electron micrograph of the device shows an X-shaped resonator. In coupling measurements, a network analyzer drives and detects one mode while a signal generator excites a second mode. (b) Transmission measurement of the device with background removed. The resonator exhibits a wide array of modes at frequencies up to 4 GHz.

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  1. Energy measurement in nonlinearly coupled nanomechanical modes
    A. Gaidarzhy, J. Dorignac, G. Zolfagharkhani, M. Imboden and P. Mohanty, Appl. Phys. Lett., 98 (26), 264106 (2011), APL

  2. Anharmonic modal coupling in a bulk micromechanical resonator
    T. Dunn, J. Wenzler and P. Mohanty, Appl. Phys. Lett., 97 (12), 123109 (2010), APL

  3. Arbitrary distribution and nonlinear modal interaction in coupled nanomechanical resonators
    J. Dorignac, A. Gaidarzhy, and P. Mohanty, J. Appl. Phys. 105, 103520 (2009), J. Appl. Phys.

  4. Quantum Nanomechanics
    P. Mohanty, In ‘Applications of Nonlinear Dynamics’, edited by V. In, P. Longhini, and A. Palacios (Springer, Berlin, 2009), p. 25., condmat local pdf