Using the Franck-Hertz Experiment To Illustrate Quantization Energy States of the Neon Atom by Electron Impact

na provide students with motivation for the study of quantum mechanics. That microscopic matter exists in quantized states can be demonstrated with modem versions of historic experiments: atomic line spectra (I), resonance potentials, and blackbody radiation. The resonance potentials of mercury were discovered by Franck and Hertz in 1914 (2). Their experiment consisted of bombarding atoms by electrons, and detecting the kinetic energy loss of the scattered electrons (3). Prior to the Franck-Hertz experiment, spectroscopic work bv Balmer and Rvdbere revealed that atoms emitted radiatibn at discrete ekergiis. The Franck-Hertz experiment showed directly that auantized enerm levels in an atom are real, not jist optiEal artifacts. atom can be raised to excited states by inelastic collisions with electrons as well as lowered from excited states by emission of photons. The classic Franck-Hertz experiment is carried out with mercury (4-7). Here we present an experiment for the study of resonance potentials using neon.

Experiment in Quantization: Atomic Line Spectra

Laboratory exercises that confront students with decisive ouantum ohenomena nrovide valuable motivation for the kudy of quantum m&hanics. The idea that microscopic matter exists in quantized states can be demonstrated with modern versions of historic experiments: atomic line snectra. blackbodv radiation. and resonance potentials. In this experiment, we present a strikingly simple and visual method for determining the wavelength of spectral lines. This experiment not only shows the inadequacy of classical physics, but also indicates the power of optical measurements.

Quantum Energy Teleportation Between Spin Particles in a Gibbs State

Energy in a multipartite quantum system appears from an operational perspective to be distributed to some extent non-locally because of correlations extant among the system's components. This non-locality allows users to transfer, in effect, locally accessible energy between sites of different system components by local operations and classical communication (LOCC). Quantum energy teleportation is a three-step LOCC protocol, accomplished without an external energy carrier, for effectively transferring energy between two physically separated, but correlated, sites. We apply this LOCC teleportation protocol to a model Heisenberg spin particle pair initially in a quantum thermal Gibbs state, making temperature an explicit parameter. We find in this setting that energy teleportation is possible at any temperature, even at temperatures above the threshold where the particles' entanglement vanishes. This shows for Gibbs spin states that entanglement is not fundamentally necessary for energy teleportation; correlation other than entanglement can suffice. Dissonance-quantum correlation in separable states-is in this regard shown to be a quantum resource for energy teleportation, more dissonance being consistently associated with greater energy yield. We compare energy teleportation from particle A to B in Gibbs states with direct local energy extraction by a general quantum operation on B and find a temperature threshold below which energy extraction by a local operation is impossible. This threshold delineates essentially two regimes: a high temperature regime where entanglement vanishes and the teleportation generated by other quantum correlations yields only vanishingly little energy relative to local extraction and a second low-temperature teleportation regime where energy is available at B only by teleportation.

Risk Factors for Physical Restraint Use in Nursing Homes: The Impact of the Nursing Home Reform Act

This study examined the impact of the Nursing Home Reform Act of 1987 on resident-and-facility-level risk factors for physical restraint use in nursing homes. Data on the 1990 and 1993 cohorts were obtained from 268 facilities in 10 states, and data on a 1996 cohort were obtained from the Medical Expenditure Panel Survey, which sampled more than 800 nursing homes nationwide. Multivariate logistic regression models were generated for each cohort to identify the impact of resident- and facility-level risk factors for restraint use. The results indicate that the use of physical restraints continues to decline. Thirty-six percent of the 1990 cohort, 26 percent of the 1993 cohort, and 17 percent of the 1996 cohort were physically restrained. Although there was a reduced rate of restraint use from 1990 to 1996, similar resident-level factors but different facility-level factors were associated with restraint use at different points in time.