A phonon depletion effect in ultrathin heterostructures with acoustically mismatched layers

Pokatilov, Evgenii P.; Nika, Denis L.; Balandin, Alexander A.
August 2004
Applied Physics Letters;8/2/2004, Vol. 85 Issue 5, p825
Academic Journal
We demonstrate theoretically that modification of the acoustic phonon spectrum in semiconductor heterostructures with large acoustic impedance mismatch between the core and cladding layers may lead to strong phonon depletion in the core layer. The latter is achieved if the heterostructure parameters are properly tuned, i.e., the structure thickness is in nanometer scale to ensure phonon quantization and the cladding layers are acoustically “softer” than the core layer. Using a numerical solution of the elasticity equation, we show that one can achieve conditions when almost all acoustic phonon modes are squeezed in the cladding layers with the exception of a small fraction of phonons with very small wave vectors (q≤0.3 nm-1). The predicted phonon depletion effect in the core layer of the acoustically mismatched heterostructures may lead to increased carrier mobility in certain regions of the heterostructure as well as improved thermal management of heterostructure-based devices.


Related Articles

  • Optomechanics: The sound of topology. Graydon, Oliver // Nature Photonics;Oct2015, Vol. 9 Issue 10, p631 

    The article offers information on the study related to the topological properties of sound waves (phonons) and optomechanical interaction between light and sound.

  • Focusing and subwavelength imaging of surface acoustic waves in a solid-air phononic crystal. Veres, Istvan A.; Berer, Thomas; Matsuda, Osamu; Burgholzer, Peter // Journal of Applied Physics;Sep2012, Vol. 112 Issue 5, p053504 

    Focusing and subwavelength imaging of surface acoustic waves (SAWs) through a phononic crystal flat lens are discussed in the presented work. Experimental and numerical wave fields are obtained in the time-domain by an optical technique and by numerical simulations. Spatial distributions of the...

  • Flat lens for pulse focusing of elastic waves in thin plates. Dubois, M.; Farhat, M.; Bossy, E.; Enoch, S.; Guenneau, S.; Sebbah, P. // Applied Physics Letters;8/12/2013, Vol. 103 Issue 7, p071915 

    The ability of left-handed materials to overcome the diffraction limit was first considered as one of the most exciting and challenging outcomes of the negative refraction concept. Flat lens focusing of elastic waves is, however, a challenge. We demonstrate broadband focusing of elastic waves at...

  • CONSIDERAÅ¢II TEORETICE PRIVIND ABSORBÅ¢IA SUNETULUI. Borlea, Ancuţa; Rusu, Tiberiu; Şimon, Simona // Annals of 'Constantin Brancusi' University of Targu-Jiu. Enginee;2011, Issue 2, p89 

    The environmental protection represents presently one of the most serious problems, whit what is faced the humanity. The principle of sound absorption is elaborated, this followed by various types of sound absorption material, which include porous absorber, Helmholtz resonator, membrane absorber...

  • Influence of high-level injection on the impedance characteristics of GaAs-AlxGa1-xAs double-heterostructure laser diodes. Al-Alusi, Mazin R.; Darling, Robert B. // Journal of Applied Physics;2/15/1990, Vol. 67 Issue 4, p2127 

    Examines the influence of high-level injection on the impedance characteristics of double-heterostructure laser diodes. Description of a bipolar model which includes high-level injection boundary conditions appropriate to the heterojunctions of a buries-channel laser diode; Effect of...

  • Influence of complex phonon spectra on intersubband optical gain. Kisin, Mikhail V.; Gorfinkel, Vera B.; Stroscio, Michael A.; Belenky, Gregory; Luryi, Serge // Journal of Applied Physics;9/1/1997, Vol. 82 Issue 5, p2031 

    Studies the influence of complex phonon spectra on intersubband optical gain heterostructures. Comparison of the calculated gain spectra with those calculated using the bulk phonon approximation; Electron energy states in the conduction band; Spectral characteristics; Dependence of the form...

  • Dissipation and Dispersion Properties of Microinhomogeneous Media. Zaitsev, V. Yu.; Nazarov, V. E.; Shul�ga, A. E. // Acoustical Physics;May2000, Vol. 46 Issue 3, p295 

    The propagation of a harmonic elastic wave in a microinhomogeneous (defect-containing) medium is considered in the framework of the rheological model that reperesents the medium in the form of a onedimensional chain of masses connected by purely elastic elements and by Kelvin-Voigt viscoelastic...

  • Diffraction of Sound by an Elastic Cylinder Near the Surface of an Elastic Halfspace. Shenderov, E. L. // Acoustical Physics;Mar2002, Vol. 48 Issue 2, p225 

    Diffraction of an acoustic wave by an elastic cylinder near the surface of an elastic halfspace is considered. The solution relies on a Helmholtz-type integral equation and uses the Green function of an elastic halfspace. The latter function is represented in the form of an integral over the...

  • EVALUATION OF AIR COUPLED ULTRASOUND FOR COMPOSITE AEROSPACE STRUCTURE. Tat, H.; Georgeson, G.; Bossi, R. // AIP Conference Proceedings;3/3/2009, Vol. 1096 Issue 1, p912 

    Non-contact air coupled ultrasound suffers from the high acoustic impedance mismatch characteristics of air to solid interfaces. Advances in transducer technology, particularly MEMS, have improved the acoustic impedance match at the transmission stage and the signal to noise at the reception...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics