- Conference date: 19–25 September 2011
- Location: Halkidiki, (Greece)
Bloch oscillations are coherent oscillations of the position of electrons (and therefore also of the electric current) inside energy bands of a crystal under an applied constant electric field. Their frequency is proportional to the lattice constant and to the field and therefore can be tuned by an applied voltage. Damped Bloch oscillations have been observed by optical means in undoped semiconductor superlattices which are artificial crystal structures formed by growing a succession of equal periods comprising layers of at least two different semiconductors. We model Bloch oscillations in a doped superlattice by using Boltzmann‐Poisson equations and derive hydrodynamic equations for the electron, current and energy densities. For a superlattice with long scattering times, we show that the damping of Bloch oscillations is so small that nonlinearities may compensate it and provide stable oscillations of the current and energy densities. In this case, numerical solutions show that there are stable Bloch oscillations spatially confined to part of the superlattice, thereby having inhomogeneous field, charge, current density and energy density profiles. These Bloch oscillations disappear as scattering times become sufficiently short.
- Crystalline semiconductors
- Boltzmann equations
- Crystal structure
Daniel Baumann, Mark G. Jackson, Peter Adshead, Alexandre Amblard, Amjad Ashoorioon, Nicola Bartolo, Rachel Bean, Maria Beltrán, Francesco de Bernardis, Simeon Bird, Xingang Chen, Daniel J. H. Chung, Loris Colombo, Asantha Cooray, Paolo Creminelli, Scott Dodelson, Joanna Dunkley, Cora Dvorkin, Richard Easther, Fabio Finelli, Raphael Flauger, Mark P. Hertzberg, Katherine Jones‐Smith, Shamit Kachru, Kenji Kadota, Justin Khoury, William H. Kinney, Eiichiro Komatsu, Lawrence M. Krauss, Julien Lesgourgues, Andrew Liddle, Michele Liguori, Eugene Lim, Andrei Linde, Sabino Matarrese, Harsh Mathur, Liam McAllister, Alessandro Melchiorri, Alberto Nicolis, Luca Pagano, Hiranya V. Peiris, Marco Peloso, Levon Pogosian, Elena Pierpaoli, Antonio Riotto, Uroš Seljak, Leonardo Senatore, Sarah Shandera, Eva Silverstein, Tristan Smith, Pascal Vaudrevange, Licia Verde, Ben Wandelt, David Wands, Scott Watson, Mark Wyman, Amit Yadav, Wessel Valkenburg and Matias Zaldarriaga
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