@article{eprints2381,
         journal = {EPL (Europhysics Letters)},
       publisher = {IOPscience},
          author = {Young-Ho Eom and Hawoong Jeong and Henri Orland and Juyeon Yi},
          volume = {76},
          number = {2},
           pages = {325--331},
           title = {Are better conductors more rigid?},
            year = {2007},
        keywords = {PACS: 72.80.Le Polymers; organic compounds (including organic semiconductors) - 82.35.Cd Conducting polymers - 77.65.Bn Piezoelectric and electrostrictive constants },
        abstract = {The variation of the bending stiffness of various materials is studied from the point of view of the electronic band characteristics. As far as the electronically generated bending stiffness {\ensuremath{\kappa}}e (which we refer to as electro-stiffness) is concerned, the relevant factors are the orbital overlap t, the gap width u between the valence band and the conduction band, and the electron filling fraction {\ensuremath{\gamma}}. A perturbative calculation leads to the approximate expression {\ensuremath{\kappa}}e {\texttt{\char126}} t2/{$\sqrt{}$}u2 + t2. This shows that materials with a large overlap and narrow band gap should be stiffer. The electro-stiffness also depends on the electron filling-fraction. We find that {\ensuremath{\kappa}}e({\ensuremath{\gamma}}) {$\leq$} {\ensuremath{\kappa}}e(1/2). These kinds of behavior are confirmed by numerical calculations. In addition, we study the variation in the projected length of flexible molecules under a voltage bias. The nonlinear variation of the bending rigidity is shown to give rise to a length contraction or dilation, depending on the voltage bias.},
             url = {http://eprints.imtlucca.it/2381/}
}