期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
Effective-mass theory for coupled quantum dots grown on (11N)-oriented substrates 被引量:2
1
作者 李树深 夏建白 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第1期1-5,共5页
The electronic structures of coupled quantum dots grown on (11N)-oriented substrates are studied in the framework of effective-mass envelope-function theory. The results show that the all-hole subbands have the smal... The electronic structures of coupled quantum dots grown on (11N)-oriented substrates are studied in the framework of effective-mass envelope-function theory. The results show that the all-hole subbands have the smallest widths and the optical properties are best for the (113), (114), and (115) growth directions. Our theoretical results agree with the available experimental data. Our calculated results are useful for the application of coupled quantum dots in photoelectric devices. 展开更多
关键词 coupled quantum dots effective-mass theory electronic structures
下载PDF
Evaluation of electron-electron interactions in coupled quantum dots by using far-infrared spectra
2
作者 董庆瑞 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第4期1400-1404,共5页
We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the inter... We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the interactions for spin S = 1 and for spin S = O. The results support the possibility to evaluate the interactions by far-infrared spectroscopy in vertically coupled quantum dots. 展开更多
关键词 coupled quantum dots electron-electron interactions far-infrared spectra
下载PDF
Two Electrons with Spin-Orbit Interactions in InAs Coupled Quantum Dots
3
作者 赵楠 许东 朱嘉麟 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第2期361-369,共9页
We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots (CQDs) with spin-orbit interactions (SOI) by exact diagonalization method. Through the SOI... We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots (CQDs) with spin-orbit interactions (SOI) by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra. 展开更多
关键词 coupled quantum dots spin-orbital interactions
下载PDF
Symmetry and size effects on energy and entanglement of an exciton in coupled quantum dots 被引量:1
4
作者 沈曼 白彦魁 +1 位作者 安兴涛 刘建军 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期389-393,共5页
We study theoretically the essential properties of an exciton in vertically coupled Gaussian quantum dots in the presence of an external magnetic field. The ground state energy of a heavy-hole exciton is split into fo... We study theoretically the essential properties of an exciton in vertically coupled Gaussian quantum dots in the presence of an external magnetic field. The ground state energy of a heavy-hole exciton is split into four energy levels due to the Zeeman effect. For the symmetrical system, the entanglement entropy of the exciton state can reach a value of 1. However, for a system with broken symmetry, it is close to zero. Our results are in good agreement with previous studies. 展开更多
关键词 EXCITON coupled Gaussian quantum dot SYMMETRY entanglement entropy
下载PDF
Signature of symmetry of laterally coupled quantum dots in far-infrared spectrum
5
作者 Gu Li-Ying Li Yan-Fang +1 位作者 Chu Wei-Dong Wei Ying-Hui 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期477-482,共6页
We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum (FIR) of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot resu... We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum (FIR) of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot results in more coherent superpositions in the low-lying states and exhibits unique anti-crossing in the two-electron FIR spectrum modulated by a magnetic field. We also find that the Coulomb correlation effect can make the FIR spectrum of coupled quantum dot without strict parity deviate greatly from Kohn theorem, which is just contrary to the symmetric case. Our results therefore suggest that FIR spectrum may be used to determine the symmetry of coupled quantum dot and to evaluate the degree of Coulomb interaction. 展开更多
关键词 structure symmetry far-infrared spectrum coupled quantum dot Coulomb interaction
下载PDF
Terahertz wave generation in coupled quantum dots
6
作者 马玉蓉 郭世方 段素青 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期470-474,共5页
Based on coupled quantum dots, we present an interesting optical effect in a four-level loop coupled system. Both the two upper levels and the two lower levels are designed to be almost degenerate, which induces a con... Based on coupled quantum dots, we present an interesting optical effect in a four-level loop coupled system. Both the two upper levels and the two lower levels are designed to be almost degenerate, which induces a considerable dipole moment. The terahertz wave is obtained from the low-frequency component of the photon emission spectrum. The frequency of the terahertz wave can be controlled by tuning the energy levels via designing the nanostructure appropriately or tuning the driving laser field. A terahertz wave with adjustable frequency and considerable intensity (100 times higher than that of the Rayleigh line) can be obtained. It provides an effective scheme for a terahertz source. 展开更多
关键词 coupled quantum dot terahertz wave
下载PDF
Controlling the Goos-H?nchen Shift via Incoherent Pumping Field and Electron Tunneling in the Triple Coupled InGaAs/GaAs Quantum Dots
7
作者 R.Nasehi S.H.Asadpour +1 位作者 H.Rahimpour Soleimani M.Mahmoudi 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第1期55-59,共5页
We study the controlling of the Goos-Hanchen (GH) shifts in reflected and transmitted light beams in the triple coupled InGaAs/GaAs quantum dot (QD) nanostructures with electron tunneling and incoherent pumping fi... We study the controlling of the Goos-Hanchen (GH) shifts in reflected and transmitted light beams in the triple coupled InGaAs/GaAs quantum dot (QD) nanostructures with electron tunneling and incoherent pumping field. It is shown that the lateral shift can become either large negative or large positive, which can be controlled by the electron tunneling and the rate of incoherent pump field in different incident angles. It is also demonstrated that the properties of the OH shifts are strongly dependent on the probe absorption beam of the intracavity medium due to the switching from superluminal light propagation to subluminal behavior or vice versa. Our suggested system can be considered as a new theoretical method for developing a new nano-optoelectronic sensor. 展开更多
关键词 GaAs on it is of Controlling the Goos-H?nchen Shift via Incoherent Pumping Field and Electron Tunneling in the Triple coupled InGaAs/GaAs quantum dots for in
下载PDF
Single Photon Scattering in a Pair of Waveguides Coupled by a Whispering-Gallery Resonator Interacting with a Semiconductor Quantum Dot 被引量:2
8
作者 程木田 叶根龙 +1 位作者 纵卫卫 马小三 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第2期47-50,共4页
The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four ... The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented. 展开更多
关键词 of is from in Single Photon Scattering in a Pair of Waveguides coupled by a Whispering-Gallery Resonator Interacting with a Semiconductor quantum Dot mode with by
下载PDF
Quantum control of two interacting electrons in a coupled quantum dot
9
作者 宋红州 张平 +1 位作者 段素青 赵宪庚 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第9期2130-2141,共12页
Quantum-state engineering, i.e. active manipulation over the coherent dynamics of suitable quantum-mechanical systems, has become a fascinating prospect of modern physics. Here we discuss the dynamics of two interacti... Quantum-state engineering, i.e. active manipulation over the coherent dynamics of suitable quantum-mechanical systems, has become a fascinating prospect of modern physics. Here we discuss the dynamics of two interacting electrons in a coupled quantum dot driven by an external electric field. The results show that the two quantum dots can be used to prepare a maximally entangled Bell state by changing the strength and duration of an oscillatory electric field. Different from the suggestion made by Loss et al (1998 Phys. Rev. A 57 120), the present entanglement involves the spatial degree of freedom for the two electrons. We also find that the coherent tunnelling suppression discussed by Grossmann et al (1991 Phys. Rev. Lett. 67 516) persists in the two-particle case: i.e. two electrons initially localized in one dot can remain dynamically localized, although the strong Coulomb repulsion prevents them from behaving so. Surprisingly, the interaction enhances the degree of localization to a large extent compared with that in the non-interacting case. This phenomenon is referred to as the Coulomb-enhanced dynamical localization. 展开更多
关键词 coupled quantum dot dynamical localization ENTANGLEMENT
下载PDF
Coherent spectroscopy of a strongly driven triple quantum dot molecule
10
作者 解研 段素青 +1 位作者 楚卫东 杨宁 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期576-583,共8页
Based on a calculation model, we study the interference phenomena of serially coupled ∨-type and ∧-type triple quantum dots (CTQDs) driven simultaneously by a strong driving field and a weak probe field. Strongly ... Based on a calculation model, we study the interference phenomena of serially coupled ∨-type and ∧-type triple quantum dots (CTQDs) driven simultaneously by a strong driving field and a weak probe field. Strongly depending on the configuration of the three-level CTQD, the probe absorption spectra, which are shown in the tunneling current, exhibit various quantum coherence properties. In the case where the two pairs of transitions of the CTQD have a small eigenfrequency difference △ω, the double-coupling effect of the driving field results in two Autler Townes doublets and one weak Mollow triplet in one spectrum. With the value of △ω increasing, only one Autler-Townes splitting remains due to the single-coupling of the field. We also find that the effect of spontaneous emission of phonons may lead to an obvious background current, which can be used to distinguish which transition is driven by the driving field in experiment. The interesting quantum property of a CTQD revealed in our results suggests its potential applications in quantum modulators and quantum logic devices. 展开更多
关键词 coherent spectroscopy coupled quantum dots quantum transport photon assistance
下载PDF
Quantum Coupling Effect between Quantum Dot and Quantum Well in a Resonant Tunneling Photon-Number-Resolving Detector
11
作者 翁钱春 安正华 +1 位作者 熊大元 朱自强 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第10期162-165,共4页
Excited states of lnAs quantum dots (QDs) can be energetically coupled with the confined level of OaAs quantum wells (QWs) in a thin-barrier resonant tunneling diode (RTD). Single charge variation in the coupled... Excited states of lnAs quantum dots (QDs) can be energetically coupled with the confined level of OaAs quantum wells (QWs) in a thin-barrier resonant tunneling diode (RTD). Single charge variation in the coupled QD can effectively switch on/off the resonant tunneling current passing through RTD, not only for emcient single-photon detection but also for photon-number-resolving detection. We present the study of the Q,D-QW coupling effect in the quantum dot coupled resonant tunneling diode (QD-cRTD) and figure out important factors for further improving the detector performance. 展开更多
关键词 quantum Coupling Effect between quantum Dot and quantum Well in a Resonant Tunneling Photon-Number-Resolving Detector RTD QDs
下载PDF
Photoluminescence study of the In_(0.3)Ga_(0.7)As surface quantum dots coupling structure
12
作者 YANG Ying-li LIU Zeng-guang +3 位作者 WANG Guo-dong WANG Ying YUAN Qing FU Guang-sheng 《Optoelectronics Letters》 EI 2021年第5期302-307,共6页
Photoluminescence(PL)was investigated as functions of the excitation intensity and temperature for a coupling surface quantum dots(SQDs)structure which consists of one In_(0.3)Ga_(0.7)As SQDs layer being stacked on mu... Photoluminescence(PL)was investigated as functions of the excitation intensity and temperature for a coupling surface quantum dots(SQDs)structure which consists of one In_(0.3)Ga_(0.7)As SQDs layer being stacked on multi-layers of In_(0.3)Ga_(0.7)As buried quantum dots(BQDs).Accompanied by considering the localized excitons effect induced by interface fluctuation,carrier transition between BQDs and SQDs were analyzed carefully.The PL measurements confirm that there is a strong carrier transition from BQDs to SQDs and this transition leads to obvious different PL characteristics between BQDs and SQDs.These results are useful for future application of SQDs as surface sensitive sensors. 展开更多
关键词 QDS As surface quantum dots coupling structure Photoluminescence study of the In
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部