Some aspects of electron–phonon interaction in the thermal modulation spectra of molecular crystals

The details of the temperature dependent intensity and linewidth of zero‐phonon bands in molecular crystal absorption and emission spectra are considered in relation to the line shape functions observed in thermal modulation spectra. Theory suggests and experiment confirms that in the limit of the Condon and adiabatic approximations for linear electron–phonon coupling, the extraordinary temperature dependence of zero‐phonon bands may be utilized to separate them from diffuse background absorption or emission. Qualitative consideration of line broadening from quadratic electron–phonon coupling utilizing a configuration coordinate model suggests that even when these terms dominate the linear interaction, increased resolution may be obtained in a thermal modulation spectrum. The theoretical considerations are illustrated with several experimental examples and some applications of the technique are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70661/2/JCPSA6-65-12-5068-1.pd

Inelastic electron tunneling via molecular vibrations in single-molecule transistors

In single-molecule transistors, we observe inelastic cotunneling features that correspond energetically to vibrational excitations of the molecule, as determined by Raman and infrared spectroscopy. This is a form of inelastic electron tunneling spectroscopy of single molecules, with the transistor geometry allowing in-situ tuning of the electronic states via a gate electrode. The vibrational features shift and change shape as the electronic levels are tuned near resonance, indicating significant modification of the vibrational states. When the molecule contains an unpaired electron, we also observe vibrational satellite features around the Kondo resonance.Comment: 5 pages, 4 figures. Supplementary information available upon reques

Decoherence in elastic and polaronic transport via discrete quantum states

Here we study the effect of decoherence on elastic and polaronic transport via discrete quantum states. The calculations are performed with the help of nonperturbative computational scheme, based on the Green's function theory within the framework of polaron transformation (GFT-PT), where the many-body electron-phonon interaction problem is mapped exactly into a single-electron multi-channel scattering problem. In particular, the influence of dephasing and relaxation processes on the shape of the electrical current and shot noise curves is discussed in detail under the linear and nonlinear transport conditions.Comment: 11 pages, 3 figure

SOSORT consensus paper: school screening for scoliosis. Where are we today?

This report is the SOSORT Consensus Paper on School Screening for Scoliosis discussed at the 4th International Conference on Conservative Management of Spinal Deformities, presented by SOSORT, on May 2007. The objectives were numerous, 1) the inclusion of the existing information on the issue, 2) the analysis and discussion of the responses by the meeting attendees to the twenty six questions of the questionnaire, 3) the impact of screening on frequency of surgical treatment and of its discontinuation, 4) the reasons why these programs must be continued, 5) the evolving aim of School Screening for Scoliosis and 6) recommendations for improvement of the procedure

An All Digital Inelastic Electron Tunneling Spectrometer Utilizing the IEEE-488 Instrument Bus and an IBM PC-XT Controller

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments and may be found at https://aip.scitation.org/doi/10.1063/1.1139319.An easily assembled computer‐controlled tunneling spectrometer is described. Spectral acquisition time is user selectable over a wide range. Low‐resolution spectra may be taken rapidly (about 30s/scan) or very slow scans with long time exponential averaging may be chosen. Data are obtained using a two‐phase lock‐in in magnitude mode so that no phasing of the lock‐in amplifier is required. The advantages of this system are discussed and some representative data presented.K. W. Hipps. (1987). An All Digital Inelastic Electron Tunneling Spectrometer Utilizing the IEEE-488 Instrument Bus and an IBM PC-XT Controller. Review of Scientific Instruments., 58, 265-268

The molecular theory of polarized emission: Linear, circular, and magnetically induced circular polarization of emission

Quantum field theory is used to derive transition probabilities pertinent to natural and magnetically induced polarized emission. First order terms inPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22867/1/0000429.pd

The Construction and Application of a Novel Glove-Box Deposition System to the Study of Air-Sensitive Materials by Tunneling Spectroscopy

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments and may be found at https://doi.org/10.1063/1.1137895.The construction and application of a high-vacuum deposition system housed in a recirculating, catalytically scrubbed, inert-atmosphere glove box is reported. This system is specifically applied to the fabrication of tunnel diodes used in a surface vibrational spectroscopy called inelastic electron tunneling spectroscopy or lETS. Through the use of this inert-atmosphere adsorption/ fabrication system, tunneling spectra have been obtained from a variety of air-sensitive compounds adsorbed on aluminum oxide. Up to now, spectra of some of the species reported here have been unattainable by the adsorption techniques used in lETS. The test molecules employed in this study included TCNE (tetracyancethylene), TCNQ (tetracyanoquinodimethane), and CO2(CO)s' TCNE adsorbed reactively on thin-film alumina under nitrogen to form a species with a vibrational spectrum similar to that of the TCNE--2 ion, while TCNQ appears to form the monoanion under the same adsorption conditions.K. W. Hipps and Ursula Mazur. (1984). The Construction and Application of a Novel Glove-Box Deposition System to the Study of Air-Sensitive Materials by Tunneling Spectroscopy. Review of Scientific Instruments., 55, 1120-1124