Experimental Observation of Enhanced Electron–Phonon Interaction in Suspended Si Double Quantum Dots

Abstract

Silicon-based suspended double quantum dots (SDQDs) were fabricated to study and control the strength of the electron-phonon interaction. A distinctive and large inelastic tunneling was observed in single-electron transport measurement and well explained by the emission of phonons that interact strongly with electrons owing to the phonon modulation in the suspended film. The first time observation of the enhancement of the electron-phonon interaction in Si SDQDs as well as the good agreement between the experimental results and the theoretical simulations are encouraging preliminary results that allow us to envision the observation of the tailoring of the electron-phonon interaction in SDQDs.

Single-electron and quantum confinement limits in length-scaled silicon nanowires

“…Single-electron devices such as single-electron transistors (SETs), based on SiNWs, have been defined using various approaches [11][12][13]. A widely investigated approach is to pattern a NW along its length, using either constrictions [22][23][24][25] or pattern dependent oxidation (PADOX) [15,26]. The later technology utilises areas of increased stress, e.g.…”

Scaled silicon nanoelectromechanical (NEM) hybrid systems

“…Figure 2 shows suspended double quantum dots (SDQDs) built on a doubly-clamped Si beam with two side gates. The SDQD SET was fabricated on 40-nm-thick heavily-P-doped (2x10 19 cm -3 ) silicon-on-insulator (SOI) substrate by using EB lithography [11]. Bias voltages applied to the two side gates, V g1 and V g2 , control the electro-chemical potentials of the individual DQDs.…”

Resonant tunnelling features in a suspended silicon nanowire single-hole transistor

“…7,8 These nanostructures are also of great interest in investigations of the fundamental limits of signal processing, 9 and characterising electrical, mechanical and material properties at reduced dimensions. 10 Modification of suspended NW structures by the incorporation of quantum dots (QDs) provides a means to measure excited electronic states, and single-electron-phonon interactions in zero-dimensions, confined within a suspended QD cavity 7 isolated from phonon modes in the substrate. Furthermore, as these interactions are at low energies corresponding to acoustic phonon like modes, it becomes possible to probe the low-energy part of the phonon spectrum, providing a complementary technique to conventional methods, such as Raman spectroscopy.…”

“…Furthermore, as these interactions are at low energies corresponding to acoustic phonon like modes, it becomes possible to probe the low-energy part of the phonon spectrum, providing a complementary technique to conventional methods, such as Raman spectroscopy. 11 A range of phenomena may be investigated, e.g., phonon confinement, energy and band gaps, 7,12 phonon blockade of electrical conduction, 13 interactions between nanomechanical and electron motion, 14,15 and decoherence effects in quantum computation devices. 7 While suspended QDs have been widely investigated in materials such as carbon nanotubes (CNTs), 16 there are comparatively few investigations in Si.…”

“…11 A range of phenomena may be investigated, e.g., phonon confinement, energy and band gaps, 7,12 phonon blockade of electrical conduction, 13 interactions between nanomechanical and electron motion, 14,15 and decoherence effects in quantum computation devices. 7 While suspended QDs have been widely investigated in materials such as carbon nanotubes (CNTs), 16 there are comparatively few investigations in Si. 7,[17][18][19] Previous work has concentrated on n-type Si material only, using lithographically patterned QDs in crystalline Si, 7,17,18 "naturally" formed QDs in nanocrystalline Si 17 and…”