A new frequency modulation (FM) technique has been demonstrated which enhances the sensitivity of attractive mode force microscopy by an order magnitude or more. Increased is made possible operating in a moderate vacuum (<10−3 Torr), increases Q vibrating cantilever. In FM technique, cantilever serves as determining element oscillator. Force gradients acting on cause instantaneous oscillator output, demodulated with detector. Unlike conventional ‘‘slope detection,’’ offers increased...

Extension of nuclear magnetic resonance (NMR) to nanoscale samples has been a longstanding challenge because the insensitivity conventional detection methods. We demonstrated use an individual, near-surface nitrogen-vacancy (NV) center in diamond as sensor detect proton NMR organic sample located external diamond. Using combination electron spin echoes and manipulation, we showed that NV senses nanotesla field fluctuations from protons, enabling both time-domain spectroscopic measurements on...

Micromechanical cantilevers are commonly used for detection of small forces in microelectromechanical sensors (e.g., accelerometers) and scientific instruments atomic force microscopes). A fundamental limit to the is imposed by thermomechanical noise, mechanical analog Johnson which governed dissipation energy. This paper reports on measurements quality factor Q arrays silicon-nitride, polysilicon, single-crystal silicon cantilevers. By studying dependence cantilever material, geometry,...

A high-sensitivity fiber-optic displacement sensor for atomic force microscopy is described. The based on the optical interference occurring in micron-sized cavity formed between cleaved end of a single-mode fiber and microscope cantilever. As result using diode laser light source all-fiber construction, compact, mechanically robust, exhibits good low-frequency noise behavior. Peak-to-peak dc to 1 kHz bandwidth less than 0.1 Å. Images are presented demonstrating resolution graphite magnetic...

This paper discusses the principles of magnetic force microscopy (MFM) and its application to recording studies. We use ac detection method which senses gradient acting on a small tip due fields emanating from domain structure in sample. Tip fabrication procedures are described for two types tips: etched tungsten wires with sputter-deposited coating nickel wires. The shown have an apex radius order 30 nm taper half-angle approximately 3°. Lorentz-mode transmission electron tips reveals that...

A mechanical degenerate parametric amplifier has been devised which greatly increases the motional response of a microcantilever for small harmonic force excitations. The can improve detection sensitivity measurements dominated by sensor noise or backaction effects and also produce squeezed states. In an initial squeezing demonstration, thermal (Brownian motion) cantilever was reduced in one phase 4.9 dB.

In 1986 Gerd Binnig and Heinrich Rohrer shared the Nobel Prize in Physics for inventing scanning tunneling microscope discovering that it can image individual surface atoms with unprecedented resolution. The success of has led to invention a host other “scanning probe” microscopes, which rely on mechanically sharp tip over sample surface. atomic force is one most successful these new devices.

One of the oldest unresolved problems in physics is mechanism charge exchange between contacting surfaces when at least one them insulating. We describe a new technique, using force microscopy, for studying this problem with greater lateral resolution than has been previously possible. The microscope shown to have 0.2 \ensuremath{\mu}m and sensitivity detect 3 electronic charges. In contact-charging experiments tip polymethyl methacrylate, charged region was much larger expected contact area...

We have combined ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve imaging (MRI) resolution <10 nm. The converts measured data into a map of nuclear spin density, taking advantage the unique characteristics “resonant slice” that is projected outward from nanoscale tip. basic principles are demonstrated by 1 H density within individual tobacco mosaic virus particles sitting on nanometer-thick layer adsorbed hydrocarbons. This result, which...

Recent initial experiments in magnetic resonance force microscopy (MRFM) have detected the exerted by electrons and nuclei microscopic samples. The generate a signal modulating sample magnetization with standard techniques. Sample sizes of few nanograms readily signals order ${10}^{\ensuremath{-}14}$ to ${10}^{\ensuremath{-}16}$ Newtons. This article describes present status MRFM technology, particular attention feasibility detecting single-electron moments, possible applications biological imaging.

We have demonstrated that a gold scanning-tunneling-microscope tip can be used as miniature solid-state emission source for directly depositing nanometer-size structures. The mechanism is believed to field evaporation of atoms, which enhanced by the close proximity substrate. technique has been in air on Ag(111) surfaces write several thousand features with no apparent degradation tip's ability emit atoms.

A 290-nm-thick single-crystal silicon cantilever has been cooled in vacuum to a temperature of 110 mK order reduce its thermal motion and thereby improve the achievable force resolution. Since conductivity is extremely low at millikelvin temperatures, an improved optical fiber interferometer was developed measure subangstrom with powers as 2 nW. At lowest temperature, exhibited quality factor 150 000 achieved noise 220 mK, corresponding 820 zN 1 Hz bandwidth.

A force microscope has been used in a new application to deposit and image localized surface charge on insulators. The lateral resolution for imaging surpasses that of currently available techniques. By applying voltage pulses an etched nickel tip, micron-sized regions approximately 2×10−16 C were created polymethylmethacrylate single-crystal sapphire surfaces. After depositing the charge, high-contrast images charged region obtained as contours constant gradient. contrast was observed decay...

A measured force resolution of 5.6×10−18 N/Hz at 4.8 K in vacuum using a single-crystal silicon cantilever only 600 Å thick is demonstrated. The spring constant this was 6.5×10−6 N/m, or more than 1000 times smaller that typical atomic microscope cantilevers. fabrication includes the integration in-line tips so can be oriented perpendicular to sample surface. This orientation helps suppress snap-in high sensitivity realized for tip-sample distances less 100 Å.

We cool the fundamental mechanical mode of an ultrasoft silicon cantilever from a base temperature 2.2 K down to 2.9+/-0.3 mK using active optomechanical feedback. The lowest observed is consistent with limits determined by properties and measurement noise. For high feedback gain, driven motion found suppress or "squash" optical interferometer intensity noise below shot level.

A near-field optical technique, using a new type of solid immersion lens (SIL), has been developed and applied to the writing reading domains in magneto-optic material. The SIL is truncated glass sphere which serves increase numerical aperture system by n2, where n index refraction Using made from n=1.83 illuminating with 780 nm light, we have achieved 317 spot size. We resolved 500 period grating, written read 350 diameter magnetic domains. technique should be capable 125 focused size blue light.

We have developed a new technique to perform fast, reliable nanoindentation of polymer surfaces for possible applications high density data storage. In this technique, an infrared laser is focused on atomic force microscope (AFM) tip, which in contact with transparent polymethyl methacrylate (PMMA) substrate. The heat from the tip softens PMMA region, at point local pressure creates pit. pits range size several hundred angstroms 1 μm, depending pulse and loading tip. Pits been made pulses as...

Noncontact friction between a Au(111) surface and an ultrasensitive gold-coated cantilever was measured as function of tip-sample spacing, temperature, bias voltage using observations damping Brownian motion. The importance the inhomogeneous contact potential is discussed comparison made to measurements over dielectric surfaces. Using fluctuation-dissipation theorem, force fluctuations are interpreted in terms near-surface fluctuating electric fields interacting with static charge.

Micromechanical sensing of magnetic force was used to detect nuclear resonance with exceptional sensitivity and spatial resolution. With a 900 angstrom thick silicon nitride cantilever capable detecting subfemtonewton forces, single shot 1.6 x 10(13) protons achieved for an ammonium nitrate sample mounted on the cantilever. A nearby millimeter-size iron particle produced 600 tesla per meter field gradient, resulting in resolution 2.6 micrometers one dimension. These results suggest that is...

A force microscope is described which uses a fiber-optic interferometer as the cantilever displacement sensor. Low thermal drift and reduced susceptibility to laser frequency variation are achieved due small (several micrometer) size of cavity. sensitivity 1.7×10−4 Å/(Hz)1/2 observed for frequencies above 2 kHz. The rate sensor on order 3 Å/min. As an initial demonstration, laser-written magnetic domains in thin film sample TbFeCo were imaged.

A recently developed near-field optical technique, the solid immersion lens (SIL), is utilized in a realistic demonstration of data storage. Using 830 nm light, 360 spot size obtained at exit surface SIL and transferred across small air gap to spinning magneto-optical disk. Reading writing are achieved density 3.8× 108 bits/cm2 with rate 3.3×106 bits/s. The subwavelength between disk maintained media velocity 1.25 m/s by incorporating into an air-bearing slider.

High-resolution images of domains written in a magnetic thin film have been obtained for the first time using force microscopy. The sample consisted 500-Å-thick Tb19Fe81 with magnetization 109 emu/cm3. Micron-sized were thermomagnetically focused laser beam. Domain by observing interaction small vibrating magnetized iron tip. Typical observed gradients range 0.8×10−4–6×10−4 N/m and forces 10−12–10−11 N. spatial resolution technique was on order 1000 Å. This sufficient to see irregularities...