Experimental Studies of Correlation Effects in Quantum Insulators

9510355在授权期内，将在IBM制造的小型硅金属氧化物半导体场效应晶体管上探索量子绝缘体的几个问题。将研究的问题包括：(1)无序跳跃和隧道系统中近藤杂质与库仑阻塞的关系，(2)相关绝缘体中局域态和噪声的统计，(3)相关绝缘体中共振峰的线形，(4)通过两种不同路径直接测量共振隧穿和跳跃电导，(5)近藤系统中的霍尔效应和磁场驱动的金属-绝缘体相变，(6)相关绝缘体中与量子干涉相关的长度尺度。实验将包括零磁场和非零场中的线性和非线性输运测量。平衡和散粒噪声实验将从有关噪声和关联系统响应的最新理论发展的角度进行分析，以揭示量子绝缘体中关联电子输运的新问题。在本奖项期间，将通过各种实验来探索最近在非常短的晶体管中发现的、不能用电子设备的传统物理学来理解的行为。这项研究将集中在亚微米尺寸的硅晶体管(一微米=40百万分之一英寸)中的电子量子传输(电子的离散运动)。这项工作的一个重点将是非线性效应(使任何晶体管都有放大能力的质量)，这在广泛的应用中也是重要的。这一研究项目将是三个机构之间的大学和行业合作：测量将在纽约城市大学和北卡罗来纳大学教堂山分校进行，晶体管将在IBM T.J.沃森研究中心制造。***

9510355 Popovic During the grant period several problems in quantum insulators will be explored on small Si metal-oxide-semiconductor field-effect transistors fabricated at IBM. Issues that will be studied include: (1) Kondo impurity vs Coulomb blockade in disordered hopping and tunneling systems, (2) statistics of localized states and noise in correlated insulators, (3) lineshape of resonance peaks in correlated insulators, (4) direct measurement of resonant tunneling and hopping conduction via two different paths, (5) Hall effects and magnetic field driven metal-insulator transitions in Kondo systems, (6) length scales associated with quantum interference in correlated insulators. The experiments will comprise linear and non-linear transport meassurements in zero magnetic field and in non-zero field. Equilibrium and shot noise experiments will be analyzed in terms of recent theoretical developments about noise and the response of correlated systems to shed new light on the problem of correlated electron transport in quantum insulators. %%% During the period of this award, recently discovered behavior in very short transistors that cannot be understood in terms of the conventional physics of electronic devices will be explored through a variety of experiments. The research will be centered on electronic quantum transport (discrete moverment of electrons) in submicron-size silicon transistors (one micron = 40 millionths of an inch). One focus of this effort will be nonlinear effects (the quality which gives any transistor the ability to amplify), which are also significant for a wide variety of applications. This research project will be a university-industry collaboration among three institutions: the measurements will be performed at the City College of CUNY and the University of North Carolina at Chapel Hill, and the transistors will be fabricated at t he IBM T. J. Watson Research Center. ***