- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A novel design of multiplexer based on nano-scale quantum-dot cellular automata
摘要： Quantum-dot Cellular Automata (QCA) is known as one of best alternative technologies for CMOS, on nano-scale dimensions, which allows digital circuits to be designed with high speed and density. In this paper, a novel 2:1 multiplexer in QCA technology is proposed. This proposed QCA multiplexer uses a new formulation based on an introduced MV32 gate. The MV32 gate has three inputs and two outputs and operates based on cell interactions. A multi-layer design for proposed 2:1 QCA multiplexer is provided. The simulation results obtained by the software, QCADesigner 2.0.3, confirm that the proposed multiplexer works well and can be applied as a high performance design, in QCA technology. Moreover, the 2:1 QCA multiplexer is used to create 4:1 and 8:1 QCA multiplexers. The results of comparisons show that the proposed structures have so better performance than many previous designs.
关键词： multiplexer,circuit design,Quantum-dot Cellular Automata (QCA),nanotechnology
更新于2025-09-10 09:29:36
-
Enhanced performance of a quantum-dot-based nanomotor due to Coulomb interactions
摘要： We study the relation between quantum pumping of charge and the work exchanged with the driving potentials in a strongly interacting ac-driven quantum dot. We work in the large-interaction limit and in the adiabatic pumping regime, and we develop a treatment that combines the time-dependent slave-boson approximation with linear response in the rate of change in the ac potentials. We find that the time evolution of the system can be described in terms of equilibrium solutions at every time. We analyze the effect of the electronic interactions on the performance of the dot when operating as a quantum motor. The main two effects of the interactions are a shift of the resonance and an enhancement of the efficiency with respect to a noninteracting dot. This is due to the appearance of additional ac parameters accounting for the interactions that increase the pumping of particles while decreasing the conductance.
关键词： slave-boson approximation,quantum pumping,quantum dot,adiabatic pumping regime,quantum motor,electronic interactions
更新于2025-09-09 09:28:46
-
Strain-tunable quantum integrated photonics
摘要： Semiconductor quantum dots are crucial parts of the photonic quantum technology toolbox, as they show excellent single photon emission properties in addition to their potential as solid state qubits. Recently, there has been an increasing effort to deterministically integrate single semiconductor quantum dots into complex photonic circuits. Despite rapid progress in the field, it remains challenging to manipulate the optical properties of waveguide-integrated quantum emitters, in a deterministic, reversible, and non-intrusive manner. Here we demonstrate a new class of hybrid quantum photonic circuits combining III-V semiconductors, silicon nitride, and piezoelectric crystals. Using a combination of bottom-up, top-down, and nanomanipulation techniques, we realize strain tuning of a selected, waveguide-integrated, quantum emitter and a planar integrated optical resonator. Our findings are an important step toward realizing reconfigurable quantum integrated photonics, with full control over the quantum sources and the photonic circuit.
关键词： ring resonator,nanowires,strain tuning,quantum dot,single photon,quantum integrated photonics
更新于2025-09-09 09:28:46
-
Characterization of electron charging and transport properties of Si-QDs with phosphorus doped Ge core
摘要： We formed high-density Si quantum dots (Si-QDs) with undoped and P-doped Ge cores on thermally-grown SiO2 by controlling low pressure chemical vapor depositions of Si and Ge. Doping into the Ge core was carried out during selective-growth of Ge on pre-grown Si-QDs. From hard x-ray photoelectron spectroscopy measurements, we con?rmed phosphorus incorporation into the Ge core, where phosphorus donor concentration in the Ge core was roughly estimated to be ～0.09 at%. When the surfaces of Si-QDs with undoped and P-doped Ge cores were scanned with an Rh-coated tip biased at 0 V, the surface potential of Si-QDs with P-doped Ge cores were increased by ～30 mV, while that of Si-QDs with undoped Ge cores remained unchanged. These results indicate that an electron was extracted from the conduction band of the Ge core due to a phosphorus donor. In the current images measured with the Rh-coated tip, the current level of Si-QDs with P-doped Ge cores on n-Si(100) substrates was higher than that of Si-QDs with undoped Ge cores. This result indicates that phosphorus donor can contribute to an increase in the electron injection rate from the Si-substrate.
关键词： Ge core,Si quantum dot,surface potential,doping,electron transport
更新于2025-09-09 09:28:46
-
Logic Sensing of MicroRNA in Living Cells Using DNA-Programmed Nanoparticle Network with High Signal Gain
摘要： Molecular circuits capable of implementing Boolean logic in cellular environments have emerged as an important tool for in situ sensing, elucidating, and modulating cell functions. The performance of existing molecular computation devices in living cells is limited because of the low level of biomolecular inputs and moderate signal gain. Herein, we devised a new class of DNA-programmed nanoparticle network with integrated molecular computation and signal amplification functions for logic sensing of dual microRNA (miRNA) molecules in living cells. The nanoparticle network, which is composed of DNA-bridged gold nanoparticles and quantum dots (QDs), could simultaneously interface with two miRNA molecules, amplify the molecular inputs, perform a calculation through AND logic gate, and generate QD photoluminescence (PL) as an output signal. Significant improvement in imaging sensitivity is achieved by integrating the signal amplifier into the molecular computation device. It allows discrimination of specific cancer cell type via intelligent sensing of miRNA patterns in living cells.
关键词： assembly,microRNA,DNA,cancer imaging,gold nanoparticle,logic gate,quantum dot
更新于2025-09-09 09:28:46
-
Nanoscale engineering of photoelectron processes in quantum well and dot structures for sensing and energy conversion
摘要： Advanced selective doping provides effective tool for nanoscale engineering of potential barriers and photoelectron processes in quantum well (QW) and quantum dot (QD) optoelectronic nanomaterials for IR sensing and wide band photovoltaic conversion. Photoelectron kinetics and device characteristics are theoretically and experimentally investigated. Asymmetrical doping of QWs is employed in a double QW structure for tuning electron transitions in QWs by voltage bias. These QW devices demonstrate bias-tunable multi-color detection and capability of remote temperature sensing. The QD structures with bipolar doping are proposed to independently control photocarrier lifetime (photocurrent) and dark current. The bipolar doping allows us to increase the height of nanoscale potential barriers around QDs without changing the electron population in QDs, which determines dark current. The QD devices with bipolar doping demonstrate significant enhancement of photocurrent, while dark current is close to that in corresponding reference devices with unipolar doping.
关键词： quantum well,photovoltaic conversion,IR sensing,selective doping,quantum dot
更新于2025-09-04 15:30:14
-
Optimization of a Solution-Processed Quantum-Dot Light-Emitting-Diode with an Inverted Structure
摘要： Colloidal quantum-dot based light-emitting diodes (QD-LEDs) are attractive for use in display devices because of the remarkable electrical and optical characteristics of colloidal quantum dots. An inverted structure may be one method to achieve the necessary multilayer device structures in QD-LEDs. In this study, each layer of an inverted-structure QD-LED was optimized. The effect of the solvent on the hole transfer layer was investigated, along with the effect of the concentration of the electron transfer layer, the effect of the co-solvent on the hole transfer layer, and the effect of the concentration and solvent of quantum dot layer. The quantum dots and ZnO NPs were synthesized as the emitting layer and carrier transporting layer using a solution-mediated process. The inverted QD-LED device showed a luminance of 3,762 cd/m2, current ef?ciency of 1.86 cd/A, and EQE of 1.18%.
关键词： Inverted Structure,Solution-Process,Quantum Dot Light Emitting Diode (QD-LED)
更新于2025-09-04 15:30:14
-
Preparation of Ag2Se QDs with excellent aqueous dispersion stability by organic coating with aqueous ATRP
摘要： In this article, water-dispersible Ag2Se quantum dots (QDs) were prepared by the facile and environmental-friendly method. In our approach, atom transfer radical polymerization (ATRP) was adopted in aqueous media to grow polymer chains from the surface of Ag2Se QDs. The aqueous ATRP allows the very mild synthetic conditions. In the present work, the polymerization reaction of methoxy[oligo(ethylene glycol)] methacrylate (OEGMA) was carried out at room temperature under aqueous conditions after the incorporation of 2-bromopropionyl moiety as the ATRP initiator on the surface of Ag2Se QDs by the ligand exchange method. OEGMA-coated Ag2Se QDs were successfully obtained without significant morphological change. The aqueous dispersion stability of OEGMA-coated Ag2Se QDs was compared with that of conventional water-dispersible Ag2Se QDs prepared by the simple modification with 11-mercaptoundecanoic acid. As a result, OEGMA-coated Ag2Se QDs showed the extremely high aqueous dispersion stability.
关键词： Aqueous dispersion stability,Methoxy[oligo(ethylene glycol)] methacrylate,Ag2Se quantum dot,Organic coating,Aqueous atom transfer radical polymerization
更新于2025-09-04 15:30:14
-
Exosome-like Nanozyme Vesicles for H2O2-responsive Catalytic Photoacoustic Imaging of Xenograft Nasopharyngeal Carcinoma
摘要： Photoacoustic imaging (PAI) is an attractive imaging modality, which is promising for clinical cancer diagnosis due to its advantages on deep tissue penetration and fine spatial resolution. However, few tumor catalytic/responsive PAI strategies are developed. Here, we design an exosome-like nanozyme vesicle for in vivo H2O2-responsive PAI of nasopharyngeal carcinoma (NPC). The intrinsic peroxidase-like activity of graphene quantum dot nanozyme (GQDzyme) effectively converts the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) into its oxidized form in the presence of H2O2. The oxidized ABTS exhibits strong near-infrared (NIR) absorbance, rendering it to be an ideal contrast agent for PAI. Thus, GQDzyme/ABTS nanoparticle is a novel type of catalytic PAI contrast agent which is sensitive to H2O2 produced from NPC cells. Furthermore, we develop an approach to construct exosome-like nanozyme vesicle via biomimetic functionalization of GQDzyme/ABTS nanoparticle with natural erythrocyte membrane modified with folate acid. In vivo animal experiments demonstrated that, this exosome-like nanozyme vesicle effectively accumulated in NPC and selectively triggered catalytic PAI for NPC. In addition, our nanozyme vesicle exhibits excellent biocompatibility and stealth ability for long blood circulation. Together, we demonstrate that GQDzyme/ABTS based exosome-like nanozyme vesicle is an ideal nanoplatform for developing deep-tissue tumor-targeted catalytic PAI in vivo.
关键词： photoacoustic imaging,nasopharyngeal carcinoma,H2O2-responsive,graphene quantum dot nanozyme,exosome-like vesicle,erythrocyte membranes
更新于2025-09-04 15:30:14
-
Facile Synthesis of Luminescent CdSeS/Polystyrene Composite Microspheres by Use of Butan-1-ol
摘要： Quantum dot/polymer composites combine the desirable optical properties of quantum dots with the surface properties of colloidal polymer microspheres. The use of the medium polarity solvent, butan-1-ol, facilitates dispersion polymerization of 0.7 μm carboxylated polystyrene/CdSeS composites–the first example of polymer composites with ternary alloyed quantum dots synthesized by dispersion polymerization.
关键词： Polystyrene,Quantum Dot,Dispersion Polymerization,Composite
更新于2025-09-04 15:30:14