相关论文: Motion backwards in time? A second example
We report the first observation of the Quantum Zeno and Anti-Zeno effects in an unstable system. Cold sodium atoms are trapped in a far-detuned standing wave of light that is accelerated for a controlled duration. For a large acceleration…
We present optical data which shows that G", the optical counterpart of the gamma-ray pulsar Geminga, pulses in B with a period of 0.237 seconds. The similarity between the optical pulse shape and the gamma-ray light curve indicates that a…
Here we consider EAS events with energy above 1E17 eV with recorded pulses delayed by t>=5 mcs in scintillation detectors with different thresholds: 10, 5 and 1.8 MeV. In order to identify pulses from electrons, muons and neutrons,…
A curious effect is uncovered by calculating the it time evolving probability of reflection of a Gaussian wave packet from a rectangular potential barrier while it is perturbed by reducing its height. A time interval is found during which…
Impressive pictures of moving Bose-Einstein condensates have been taken using phase-contrast imaging M. R. Andrews et al., Science 273, 84 (1996). We calculate the quantum backaction of this measurement technique. We find that…
The next generation of radiographic machines based on induction accelerators is expected to generate multiple, small diameter x-ray spots of high intensity. Experiments to study the interaction of the electron beam with plasmas generated at…
When a pulse of light traverses a material, it incurs a time delay referred to as the group delay. Should the group delay experienced by photons be attributed to the time they spend as atomic excitations? However reasonable this connection…
Laser-accelerated electron beams have been created at a kHz repetition rate from the {\it reflection} of intense ($\sim10^{18}$ W/cm$^2$), $\sim$40 fs laser pulses focused on a continuous water-jet in an experiment at the Air Force Research…
The transition probability for the emission of a Bessel photon by an atomic system is calculated within first order perturbation theory. We derive a closed expression for the electromagnetic potentials beyond the paraxial approximation that…
We briefly review the pilot ideas on the generation of EM-pulses much shorter than already available sub-femtosecond pulses, and outline inroads and venues into the physics of pulses mush shorter than an attosecond (10^-18 s), in particular…
Two recent experiments have reported the trapping of individual atoms inside optical resonators by the mechanical forces associated with single photons [Hood et al., Science 287, 1447 (2000) and Pinkse et al., Nature 404, 365 (2000)]. Here…
Einstein's weak equivalence principle (EEP) can be tested through the arrival time delay between photons with different frequencies. Assuming that the arrival time delay is solely caused by the gravitational potential of the Milky Way, we…
We present accurate measurements of the relative motion and deformation of two large bubbles released consecutively in a quiescent liquid confined in a thin-gap cell. Though the second bubble injected is smaller, we observed that in all…
We introduce the concept of a quantum walk with two particles and study it for the case of a discrete time walk on a line. A quantum walk with more than one particle may contain entanglement, thus offering a resource unavailable in the…
The large observed redshift of quasars has suggested large cosmological distances and a corresponding enormous energy output to explain the brightness or luminosity as seen at earth. Alternative or complementary sources of redshift have not…
We have trapped cesium atoms over many minutes in the focus of a CO$_2$-laser beam employing an extremely simple laser system. Collisional properties of the unpolarized atoms in their electronic ground state are investigated. Inelastic…
An absorption of a weak pulse by two identical atoms moving in a trap is investigated. Based on atom-light interactions we present a microscopic model of a two-body wave function diagnosis. We study the influence of pulse properties on the…
The development of attosecond technology has enabled the real-time observation of coherent electron motion in atoms, molecules and condensed phases. Experimentally, it is now possible to generate laser pulses of durations of only a few tens…
Humans will launch spacecraft that travel at an appreciable fraction of the speed of light. Spacecraft traffic will be tracked by radar. Scattering of pulsed electromagnetic fields by an object in uniform translational motion at…
Vaidman's analysis of the photon's past is based on incorrect interpretation of quantum probability amplitudes. The confusion stems from his original work [{\it Phys. Rev. Lett.} \textbf{60}, 1351 (1988)], which missed the connection…