Atoms in an amplitude-modulated standing wave - dynamics and pathways to quantum chaos

AbstractOptical microcavities play a significant role in the study of classical and quantum chaos. To date, most experimental explorations of their internal wave dynamics have focused on the properties of their inputs and outputs, without directly interrogating the dynamics and the associated mode patterns inside. As a result, this key information is rarely retrieved with certainty, which significantly restricts the verification and understanding of the actual chaotic motion. Here we demonstrate a simple and robust approach to directly and rapidly map the internal mode patterns in chaotic microcavities. By introducing a local index perturbation through a pump laser, we report a spectral response of optical microcavities that is proportional to the internal field distribution. With this technique, chaotic modes with staggered mode spacings can be distinguished. Consequently, a complete chaos assisted tunneling (CAT) and its time-reversed process are experimentally verified in the optical domain with unprecedented certainty.

Download Full-text

MinE recruits, stabilizes, releases, and inhibits MinD interactions with membrane to drive oscillation

10.1101/109637 ◽

2017 ◽

Cited By ~ 2

Author(s):

Anthony G. Vecchiarelli ◽

Min Li ◽

Michiyo Mizuuchi ◽

Vassili Ivanov ◽

Kiyoshi Mizuuchi

Keyword(s):

Escherichia Coli ◽

Standing Wave ◽

Traveling Waves ◽

Wide Spectrum ◽

Toggle Switch ◽

Wave Dynamics ◽

Wave Oscillator ◽

The Mind ◽

Artificial Bilayers

SUMMARYThe MinD and MinE proteins ofEscherichia coliself-organize into a standing-wave oscillator on the membrane to help align division at mid-cell. When unleashed from cellular confines, we find that MinD and MinE form a wide spectrum of patterns on artificial bilayers - static amoebas, traveling waves, traveling mushrooms, and bursts with standing-wave dynamics. We recently focused our cell-free studies on bursts because their dynamics closely resemble those foundin vivo. The data unveiled a patterning mechanism largely governed by MinE regulation of MinD interaction with membrane. We proposed that the MinD to MinE ratio on the membrane acts as a toggle switch between MinE-stimulated recruitment or release of MinD from the membrane. Here we provide data that further refines and extends our model that explains the remarkable spectrum of patterns supported by these two ‘simple’ proteins.

Download Full-text

Eels Under Standing Wave Conditions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054911 ◽

1982 ◽

Vol 40 ◽

pp. 492-495

Author(s):

O.L. Krivanek ◽

J. TaftØ

Keyword(s):

Standing Wave ◽

Wave Conditions ◽

Set Up ◽

A Site ◽

Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Download Full-text

Voltage and Orientation Dependence of Characteristic X-Ray Production in Thin Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118941 ◽

1985 ◽

Vol 43 ◽

pp. 414-415

Author(s):

G. Thomas ◽

K. M. Krishnan ◽

Y. Yokota ◽

H. Hashimoto

Keyword(s):

Standing Wave ◽

Incident Beam ◽

Orientation Dependence ◽

Incident Plane Wave ◽

Crystalline Materials ◽

X Ray ◽

Incident Plane ◽

Crystal Unit Cell ◽

Beam Orientation ◽

Acceleration Voltage

For crystalline materials, an incident plane wave of electrons under conditions of strong dynamical scattering sets up a standing wave within the crystal. The intensity modulations of this standing wave within the crystal unit cell are a function of the incident beam orientation and the acceleration voltage. As the scattering events (such as inner shell excitations) that lead to characteristic x-ray production are highly localized, the x-ray intensities in turn, are strongly determined by the orientation and the acceleration voltage. For a given acceleration voltage or wavelength of the incident wave, it has been shown that this orientation dependence of the characteristic x-ray emission, termed the “Borrmann effect”, can also be used as a probe for determining specific site occupations of elemental additions in single crystals.

Download Full-text

3-D optical transfer in excitation field synthesis microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136696 ◽

1995 ◽

Vol 53 ◽

pp. 64-65

Author(s):

Vijay Krishnamurthi ◽

Brent Bailey ◽

Frederick Lanni

Keyword(s):

Standing Wave ◽

Spatial Information ◽

3D Structure ◽

Complete Recovery ◽

Weighting Factor ◽

Optical Transfer Function ◽

Excitation Field ◽

Optical Transfer ◽

Set Up ◽

Focus Plane

Excitation field synthesis (EFS) refers to the use of an interference optical system in a direct-imaging microscope to improve 3D resolution by axially-selective excitation of fluorescence within a specimen. The excitation field can be thought of as a weighting factor for the point-spread function (PSF) of the microscope, so that the optical transfer function (OTF) gets expanded by convolution with the Fourier transform of the field intensity. The simplest EFS system is the standing-wave fluorescence microscope, in which an axially-periodic excitation field is set up through the specimen by interference of a pair of collimated, coherent, s-polarized beams that enter the specimen from opposite sides at matching angles. In this case, spatial information about the object is recovered in the central OTF passband, plus two symmetric, axially-shifted sidebands. Gaps between these bands represent "lost" information about the 3D structure of the object. Because the sideband shift is equal to the spatial frequency of the standing-wave (SW) field, more complete recovery of information is possible by superposition of fields having different periods. When all of the fields have an antinode at a common plane (set to be coincident with the in-focus plane), the "synthesized" field is peaked in a narrow infocus zone.

Download Full-text