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- 摘要
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- 实验方案
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Coherent phonon lasing in a thermal quantum nanomachine
摘要： The notion of nanomachines has recently emerged to engage and use collective action of ensembles of nanoscale components or systems. Here we present a heat-gradient driven nanomachine concept which through appropriate coupling between quantum nanosystems is capable of realizing and maintaining an inversion. Based on a Lindblad form of the quantum master equation with a semiclassical coupling to the lattice displacement phonon field we show that this positive inversion can be harnessed to generate coherent optomechanical oscillations and phonon lasing.
关键词： heat-gradient,nanomachines,quantum nanosystems,quantum master equation,Lindblad form,phonon lasing
更新于2025-09-23 15:21:01
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Highly Flexible and Voltage Based Wavelength Tunable Biosensor
摘要： A plasmonic absorber as a biosensor based on the highly flexible electro-optic material is numerically investigated. The structure demonstrates multispectral high absorption in visible and unity absorption in the near-infrared range. The resonant wavelengths are extremely sensitive to the applied voltage, variation in geometric parameters, and the refractive index of the background material, resulting in wavelength-tunable absorption that can be used for tunable sensors and filters. The refractive index based sensitivity is calculated on different voltages to adjust the resonances to the desired point in a wide waveband for detecting a large number of different biomaterials. The electro-optic tunability can be used to reduce fabrication errors and use of scaling. In addition, strong field absorption, broad resonant peaks, and wide incident angle absorption versatility are found in the proposed structure which can be applied for energy harvesting, infra-red detection, and surface-enhanced Raman spectroscopy purposes.
关键词： electro-optic,plasmonics,detection,photonics,nanosystems,metasurface
更新于2025-09-19 17:15:36
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Light-induced Polymer Response Through Thermoplasmonics Transduction in Highly Monodisperse Core-Shell-Brush Nanosystems
摘要： Smart nanosystems that transduce external stimuli to physical changes are an inspiring challenge in current materials chemistry. Hybrid organic-inorganic materials attract great attention due to the combination of building blocks responsive to specific external solicitations. In this work, we present a sequential method for obtaining an integrated core-shell-brush nanosystem that transduces light irradiation into a particle size change through a thermoplasmonic effect. We first synthetize hybrid monodisperse systems made up of functionalized silica colloids covered with controllable thermo-responsive Poly(N-isopropylacrylamide), PNIPAm, brushes, produced through radical photopolymerization. This methodology was successfully transferred to Au@SiO2 nanoparticles, leading to a core-shell-brush architecture, in which the Au core acts as a nano-source of heat; the silica layer, in turn, adapts the metal and polymer interfacial chemistries and can also host a fluorescent dye for bioimaging. Upon green LED irradiation, a light-to-heat conversion process leads to the shrinkage of the external polymer layer, as proven by in situ DLS. Our results demonstrate that modular hybrid nanosystems can be designed and produced with photo-thermo-physical transduction. These remote-controlled nanosystems present prospective applications in smart carriers, responsive bioscaffolds or soft robotics.
关键词： photothermal effect,hybrid materials,in-situ DLS,UV-photo induced polymerization,core-shell-brush colloids,Smart nanosystems
更新于2025-09-19 17:13:59
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Backaction effects in cavity-coupled quantum conductors
摘要： We study the electronic transport through a pair of distant nanosystems (Sa and Sb) embedded in a single-mode cavity. Each system is connected to source and drain particle reservoirs and the electron-photon coupling is described by the Tavis-Cummings model. The generalized master equation approach provides the reduced density operator of the double system in the dressed-states basis. It is shown that the photon-mediated coupling between the two subsystems leaves a signature on their transient and steady-state currents. In particular, a suitable bias applied on subsystem Sb induces a photon-assisted current in the other subsystem Sa which is otherwise in the Coulomb blockade. We also predict that a transient current passing through one subsystem triggers a charge transfer between the optically active levels of the second subsystem even if the latter is not connected to the leads. As a result of backaction, the transient current through the open system develops Rabi oscillations (ROs) whose period depends on the initial state of the closed system.
关键词： Rabi oscillations,Coulomb blockade,nanosystems,photon-mediated coupling,electronic transport,Tavis-Cummings model
更新于2025-09-12 10:27:22
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Coherent multidimensional spectroscopy of dilute gas-phase nanosystems
摘要： Two-dimensional electronic spectroscopy (2DES) is one of the most powerful spectroscopic techniques with unique sensitivity to couplings, coherence properties and real-time dynamics of a quantum system. While successfully applied to a variety of condensed phase samples, high precision experiments on isolated systems in the gas phase have been so far precluded by insufficient sensitivity. However, such experiments are essential for a precise understanding of fundamental mechanisms and to avoid misinterpretations. Here, we solve this issue by extending 2DES to isolated nanosystems in the gas phase prepared by helium nanodroplet isolation in a molecular beam-type experiment. This approach uniquely provides high flexibility in synthesizing tailored, quantum state-selected model systems of single and many-body character. In a model study of weakly-bound Rb2 and Rb3 molecules we demonstrate the method’s unique capacity to elucidate interactions and dynamics in tailored quantum systems, thereby also bridging the gap to experiments in ultracold quantum science.
关键词： Two-dimensional electronic spectroscopy,helium nanodroplet isolation,gas-phase nanosystems,ultracold quantum science,Rb2 and Rb3 molecules
更新于2025-09-10 09:29:36
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Photosynthetic Machineries in Nano-Systems
摘要： Photosynthetic reaction centres are membrane-spanning proteins, found in several classes of autotroph organisms, where a photoinduced charge separation and stabilization takes place with a quantum efficiency close to unity. The protein remains stable and fully functional also when extracted and purified in detergents thereby biotechnological applications are possible, for example, assembling it in nano-structures or in optoelectronic systems. Several types of bio-nanocomposite materials have been assembled by using reaction centres and different carrier matrices for different purposes in the field of light energy conversion (e.g., photovoltaics) or biosensing (e.g., for specific detection of pesticides). In this review we will summarize the current status of knowledge, the kinds of applications available and the difficulties to be overcome in the different applications. We will also show possible research directions for the close future in this specific field.
关键词： Bio-nanocomposite,reaction centre,nanosystems,photosynthesis
更新于2025-09-04 15:30:14