Gordon Conference Magnetic Resonance 14-19 June 2009, University of New England, Biddeford, ME
FOMMS 2009 Conference, July 12-16, 2009,Semiahmoo Resort in Blaine, WA
51st Annual Rocky Mountain Conference on Analytical ChemistryJuly 19-23, 2009 in Snowmass, CO
Nature 459, 683-685 (4 June 2009), Entangled mechanical oscillators, J. D. Jost, J. P. Home, J. M. Amini, D. Hanneke, R. Ozeri2 C. Langer, J. J. Bollinger, D. Leibfried and D. J. Wineland,
Hallmarks of quantum mechanics include superposition and entanglement. In the context of large complex systems, these features should lead to situations as envisaged in the 'Schrödinger's cat'1 thought experiment (where the cat exists in a superposition of alive and dead states entangled with a radioactive nucleus). Such situations are not observed in nature. This may be simply due to our inability to sufficiently isolate the system of interest from the surrounding environment2, 3—a technical limitation. Another possibility is some as-yet-undiscovered mechanism that prevents the formation of macroscopic entangled states4. Such a limitation might depend on the number of elementary constituents in the system5 or on the types of degrees of freedom that are entangled. Tests of the latter possibility have been made with photons, atoms and condensed matter devices6, 7. One system ubiquitous to nature where entanglement has not been previously demonstrated consists of distinct mechanical oscillators. Here we demonstrate deterministic entanglement of separated mechanical oscillators, consisting of the vibrational states of two pairs of atomic ions held in different locations. We also demonstrate entanglement of the internal states of an atomic ion with a distant mechanical oscillator. These results show quantum entanglement in a degree of freedom that pervades the classical world. Such experiments may lead to the generation of entangled states of larger-scale mechanical oscillators8, 9, 10, and offer possibilities for testing non-locality with mesoscopic systems11. In addition, the control developed here is an important ingredient for scaling-up quantum information processing with trapped atomic ions12, 13, 14.
J. Vac. Sci. Technol. B Volume 27, Issue 3, pp. 1408-1412 (May 2009), Integrated microactuation scanning probe microscopy system, Xing Chen and Dong-Weon Lee MEMS and Nanotechnology Laboratory, Department of Mechanical Engineering, Chonnam National University, 300 Yongbong, Buk, Gwangju 500-757, Republic of Korea,
This article reports on a highly integrated system that combines a scanning probe cantilever with an X-Y-Z scanner through monolithic microfabrication without any manual assembly or alignment for scanning probe microscopy. This compact system included an integrated scanning probe cantilever with a sharp tip and an electrostatic comb-drive microstage with a novel structure that enables both a large in-plane displacement and out-of-plane actuation even for tilt motion. Additionally, interdigitated comb-drive capacitors allow for sensitive self-sensing on both the translational position and vertical height without any external detectors or special extra integrated sensors. The cantilever, with a sharp tip fabricated by new hybrid wet and dry etching, was developed for the scanning probe system. The authors successfully demonstrated the miniaturized scanning probe microscopy system to show how microelectromechanical system techniques have an influence on the conventional bulk system and macroscopic instruments.
PHYSICAL REVIEW B 79, 165309 2009Nanoscience Institute, California Institute of Technology, Pasadena, California 91125, USA
Two elastically coupled nanomechanical resonators driven independently near their resonance frequencies
show intricate nonlinear dynamics. The dynamics provide a scheme for realizing a nanomechanical system
with tunable frequency and nonlinear properties. For large vibration amplitudes, the system develops spontaneous
oscillations of amplitude modulation that also show period-doubling transitions and chaos. The complex
nonlinear dynamics are quantitatively predicted by a simple theoretical model.
PHYSICAL REVIEW B
79, 132401 2009
Detection of localized ferromagnetic resonance
in a continuous thin film via magnetic resonance force microscopy, E.
Nazaretski,1 D. V. Pelekhov,2 I. Martin,1 M. Zalalutdinov,3 D. Ponarin,4
A. Smirnov,4 P. C. Hammel,2 and R. Movshovich1 1Los Alamos National
Laboratory, Los Alamos, New Mexico 87545, USA 2Department of Physics,
Ohio State University, Columbus, Ohio 43210, USA 3SFA Inc., Crofton,
Maryland 21114, USA 4Department of Chemistry, North Carolina State
University, Raleigh, North Carolina 27695, USA Received 15 August 2008;
published 2 April 200 MRF measurements of ferromagnetic resonance in a
50 nm thick permalloy film tilted with respect to the direction of the
external magnetic field. At small probe-sample distances the MRFM
spectrum breaks up into multiple modes, which we identify as local
ferromagnetic resonances confined by the magnetic field of the MRFM tip.
Micromagnetic simulations support this identification of the modes and
show they are stabilized in the region where the dipolar tip field has a
component antiparallel to the applied field.
PHYSICAL REVIEW B 79, 094304, 2009, Theoretical basis of parametric-resonance-based atomic force microscopy, G. Prakash, S. Hu, A. Raman, R. Reifenberger,Parametric resonance underpins the physics of swings, resonant surface waves, and particle traps. There is increasing interest in its potential applications in atomic force microscopy AFM . In this paper, the dynamics of parametrically resonant microcantilevers for high sensitivity imaging and force spectroscopy applications is investigated theoretically. Detailed numerical parametric-resonance simulations are performed to understand how the microcantilever amplitude varies with tip-sample separation, the tip-sample interaction, and the scanning dynamics of a microcantilever probe. We find three key advantages of a parametrically resonant microcantilever for AFM applications: a the reduction in ringing effects near feature edges that occur for high-Q microcantilevers; b an increase in the scanning speed while maintaining a low tip-sample interaction force while imaging; and c an enhanced sensitivity to long-range magnetic and electrostatic force gradients acting between the tip and the sample. Experimental results are presented with an aim to clearly identify the advantages and disadvantages that parametric resonance offers for scanning probe applications.
Labels: MRFM-related publications
