bias-induced optical absorption of current carrying two-orbital quantum dot with strong electron-phonon interaction (polaron regime)

نویسندگان

a. eskandari-asl

department of physics, faculty of sciences, university of shahid beheshti, tehran, islamic republic of iran

چکیده

the one photon absorption (opa) cross section of a current carrying two-orbital quantum dot (qd) with strong electron-phonon interaction (polaron regime) is considered. using the self-consistent non-equilibrium hartree-fock (hf) approximation, we determine the dependence of opa cross section on the applied bias voltage, the strength of effective electron-electron interaction, and level spacing of qd. our numerical results reveal a unique property that there are two distinct regimes for opa. we find that for values of level spacing of qd smaller than half the strength of effective electron-electron interaction and all values of applied bias voltage, the absorption is due to the excitation of the plasmon modes of the system with low cross section, but for the values of level spacing larger than the aforementioned value, within a finite range of the applied bias voltage, set by the values of level spacing and the strength of electron-electron interaction, the opa is due to electron transition between the two orbitals of qd with an order of magnitude larger cross section than the former case. this property results in an almost square shape cross section as a function of applied bias, for peak values of absorption at resonance frequencies.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Bias-Induced Optical Absorption of Current Carrying Two-Orbital Quantum Dot with Strong Electron-Phonon Interaction (Polaron Regime)

The one photon absorption (OPA) cross section of a current carrying two-orbital quantum dot (QD) with strong electron-phonon interaction (polaron regime) is considered. Using the self-consistent non-equilibrium Hartree-Fock (HF) approximation, we determine the dependence of OPA cross section on the applied bias voltage, the strength of effective electron-electron interaction, and level spacing ...

متن کامل

Entanglement production under electron phonon interaction in a quantum dot

We consider the quantum dot entangler device introduced by Oliver et al. [1] coupled to a single phonon mode. While we take the phonon interaction to all orders, we perform a fourth order calculation in electron-dot coupling. Using the Von Neumann entropy we measure the degree of entanglement. We find that the phonon mechanism habilitates single electron processes which manifest themselves as d...

متن کامل

Single-electron-phonon interaction in a suspended quantum dot phonon cavity.

An electron-phonon cavity consisting of a quantum dot embedded in a freestanding GaAs/AlGaAs membrane is characterized using Coulomb blockade measurements at low temperatures. We find a complete suppression of single electron tunneling around zero bias leading to the formation of an energy gap in the transport spectrum. The observed effect is induced by the excitation of a localized phonon mode...

متن کامل

Quantum current modeling in nano-transistors with a quantum dot

Carbon quantum dots (CQDs) serve as a new class of ‘zero dimensional’ nanomaterial’s in thecarbon class with sizes below 10 nm. As light emitting nanocrystals, QDs are assembled from semiconductormaterials, from the elements in the periodic groups of II-VI, III-V or IV-VI, mainly thanks to impacts of quantum confinement QDs have unique optical properties such as brighter, highly pho...

متن کامل

Transmission zero in a semichaotic quantum dot with strong electron-electron interaction

The pioneering experiment [Nature 385, 417 (1997)] reported the measurement of the transmission phase of the electron traversing a quantum dot and found the intriguing feature of the sudden phase drop in conductance valleys. Based on the Friedel sum rule for a spinless effective one-dimensional system, it has been previously argued [Phys. Rev. Lett. 82, 2358 (1999)] that the sudden phase drop s...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
journal of sciences islamic republic of iran

جلد ۲۸، شماره ۲، صفحات ۱۷۵-۱۸۳

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023