高增益调节系数硅单电子晶体管的输运特性

为了增强单电子晶体管中栅极和沟道量子点之间的耦合度,提高增益调节系数,发展了结合预制控制栅、电子束直写、各向异性腐蚀和热氧化的制备工艺.在室温下对器件的电学特性进行测量,观察到了典型的库仑振荡效应和负微分电导效应.基于量子点能级分立模型,分析了器件的输运原理,重点研究了强耦合作用对器件输运性质的影响.研究表明,通过控制量子点的热氧化时间,将器件量子点尺寸减小到7.6nm,增益调节系数提高到0.84.     

Linear and nonlinear transport across carbon nanotube quantum dots

We present a low energy-theory for non-linear transport in finite-size interacting single-wall carbon nanotubes. It is based on a microscopic model for the interacting p_z electrons and successive bosonization. We consider weak coupling to the leads and derive equations of motion for the reduced density matrix. We focus on the case of large-diameter nanotubes where exchange effects can be neglected. In this situation the energy spectrum is highly degenerate. Due to the multiple degeneracy, diagonal as well as off-diagonal (coherences) elements of the density matrix contribute to the nonlinear transport. At low bias, a four-electron periodicity with a characteristic ratio between adjacent peaks is predicted. Our results are in quantitative agreement with recent experiments.     

Computer-aided prediction of QT-prolongation1

Drug-induced cardiac arrhythmia is acknowledged as a serious obstacle in successful development of new drugs. Several methods for in silico prediction of acquired long QT syndrome (LQTS) caused by the pharmacological blockade of human hERG K⁺ channels are discussed in literature. We propose to use the computer program PASS, which estimates the probabilities of about 3000 biological activities, not only for prediction of hERG blockade and QT-prolongation but also for the analysis of indirect mechanisms of these actions. After addition in the PASS training set of 163 compounds with data on QT-Prolongation and re-training, it was shown that accuracy of prediction was 87.1% and 81.8% for hERG blockade and QT-prolongation, respectively. Using computer program PharmaExpert we found that in the predicted biological activity spectra there was a certain correlation between the hERG blockade and some other molecular mechanisms of action. Possible role of 1-phosphatidylinositol-4-phospate 5-kinase, dimethylargininase and progesterone 11 alpha-monooxygenase inhibition in hERG blockade was discussed.     

Quantum-dot transport in carbon nanotubes

Transport measurements on a bundle of single-walled carbon nanotubes have been made below 4.2 K as a function of side gate and source–drain bias voltage. The transport of an individual nanotube is described by the Coulomb blockade effect. The zero-dimensional quantum states of the nanotube become clear for measurements of large bias voltage. In addition, we present preliminary results of microwave application to the SWNT dot, and the results can be qualitatively explained by classical coupling to the dot.     

利用偶极封锁制备多粒子三维纠缠态

选择碱金属原子的三个稳定基态为qutrit,其里德堡态为辅助态,借助调节经典脉冲所实现的单量子比特操作和偶极封锁机制分别制备了两原子三维最大纠缠态和三原子三维最大纠缠态。     

基于应变锗空穴双量子点的可调耦合和自旋阻塞研究

应变锗空穴量子点是实现超大规模量子计算最有前景的平台之一.由于锗空穴不受超精细相互作影响，有着较长的自旋弛豫时间和量子退相干时间，且锗中本征的强旋轨道耦合和空穴载流子的低有效质量，使得全电场操控空穴自旋量子比特得以实现，极大地降低了器件加工难度，增加了量子点的可扩展性.本文介绍了一种使用应变锗异质结制备重叠栅空穴双量子点器件的方法，完成了应变锗异质结性质测量，空穴双量子点器件制作，单量子点输运性质和双量子点输运性质研究，双量子点耦合可研究调节性研究，以及外磁场存在下的漏电流性质研究和泡利自旋阻塞解除机制的研究.这些工作为未来实现高质量自旋量子比特制备和高保真度量子逻辑门操控提供了实验平台和基本参数.     

Unconventional photon blockade induced by the self-Kerr and cross-Kerr nonlinearities

We study the use of the self-Kerr and cross-Kerr nonlinearities to realize strong photon blockade in a weakly driven, four-mode optomechanical system. According to the Born−Oppenheimer approximation, we obtain the cavity self-Kerr coupling and the inter-cavity cross-Kerr coupling, adiabatically separated from the mechanical oscillator. Through minimizing the second-order correlation function, we find out the optimal parameter conditions for the unconventional photon blockade. Under the optimal conditions, the strong photon blockade can appear in the strong or weak nonlinearities.     

Polysaccharide Nanodonuts for Photochemotherapy-Amplified Immunogenic Cell Death to Potentiate Systemic Antitumor Immunity Against Hepatocellular Carcinoma

Immunotherapy shows great promise in the treatment of hepatocellular carcinoma (HCC), however, the low response rate of HCC patients to immunotherapy caused by inadequately immunogenic and immunosuppressive tumor microenvironment (TME) is a huge challenge. Herein, a donut-like multifunctional polysaccharide nanoplatform (GH-PID) is constructed from doxorubicin/aldehyde hyaluronan nanoring, indocyanine green/hydroxyethyl chitosan nanocomplex, and HCC-bitargeted galactosamine-hyaluronan conjugate via a facile self-assembly process. The GH-PID nanodonuts exhibit excellent HCC-targeted ability and synergetic photochemotherapy effect with a coefficient index of about 0.44. Moreover, near infrared laser-irradiated GH-PID nanodonuts show robust therapeutic efficacy in HCC mouse models by virtue of photochemotherapy-augmented immunogenic cell death (ICD) effect. The remarkable ICD in combination with programmed death-1 antibody efficiently eradicates primary tumors and inhibits distant tumor growth and lung metastasis of HCC by maturing dendritic cells, increasing CD8⁺ T cell infiltration, suppressing the expansion and trafficking of immunosuppressive myeloid-derived suppressor cells, and ameliorating immunosuppressive TME. This study provides a facile and versatile strategy to construct polysaccharide nanodonuts integrating multifunctionality and highly efficient HCC-targeted ability, and the nanodonuts-based ICD inducer holds great promise for potentiating systemic antitumor immunity and programmed death-1/programmed death-ligand 1 blockade efficacy.