相关论文: Electric field scaling at a B=0 metal-insulator tr…
We have studied the temperature dependence of resistivity, $\rho$, for a two-dimensional electron system in silicon at low electron densities, $n_s\sim10^{11}$ cm$^{-2}$, near the metal/insulator transition. The resistivity was empirically…
We have studied the zero magnetic field resistivity of unique high- mobility two-dimensional electron system in silicon. At very low electron density (but higher than some sample-dependent critical value, $n_{cr}\sim 10^{11}$ cm$^{-2}$),…
We report measurements of the zero-field resistivity in dilute 2D electron system in silicon at temperatures down to 35 mK. This extends the previously explored range of temperatures by almost an order of magnitude. On the metallic side,…
The temperature dependence of conductivity $\sigma (T)$ of a two-dimensional electron system in silicon has been studied in parallel magnetic fields B. At B=0, the system displays a metal-insulator transition at a critical electron density…
The parallel magnetic field tuned two-dimensional superconductor-insulator transition has been investigated in ultrathin films of amorphous Bi. The resistance is found to be independent of temperature on both sides of the transition below…
We have varied the disorder in a two-dimensional electron system in silicon by applying substrate bias. When the disorder becomes sufficiently low, we observe the emergence of the metallic phase, and find evidence for a metal-insulator…
In a recent Letter, Kravchenko et al. [cond-mat/9608101] have provided evidence for a metal-insulator transition (MIT) in a two-dimensional electron system (2DES) in Si metal-oxide-semiconductor field-effect transistors (MOSFETs). The…
We have reexamined data on the possible two dimensional metal-insulator transition at B=0 in Si-MOSFETs using a nonlinear regression method to extract all scaling parameters in a single fit. By keeping track of the magnitude of errors in…
The resistivities of the dilute, strongly-interacting 2D electron systems in the insulating phase of a silicon MOSFET are the same for unpolarized electrons in the absence of magnetic field and for electrons that are fully spin polarized by…
Two phenomena have been recently observed in high-mobility Si MOS structures: (1) strong enhancement of the metallic conduction at low temperatures, T < 2K, and (2) the scaling behavior of the temperature and electric field dependences of…
We report a detailed scaling analysis of resistivity \rho(T,n) measured for several high-mobility 2D electron systems in the vicinity of the 2D metal-insulator transition. We analyzed the data using the two parameter scaling approach and…
The critical electron density for the metal-insulator transition in a two-dimensional electron gas can be determined by two distinct methods: (i) a sign change of the temperature derivative of the resistance, and (ii) vanishing activation…
We report measurements of the resistance of silicon MOSFETs as a function of temperature in high parallel magnetic fields where the 2D system of electrons has been shown to be fully spin-polarized. A magnetic field suppresses the metallic…
A simple non-interacting-electron model, combining local quantum tunneling and global classical percolation (due to a finite dephasing time at low temperatures), is introduced to describe a metal-insulator transition in two dimensions. It…
The low-temperature resistivity of a SiGe 2-dimensional hole gas has been studied using the gate controlled carrier density as a parameter. A metal-insulator transition is seen both in the temperature and in the electric field behaviour.…
According to the scaling theory of localization, all quantum electronic states are localized in two-dimensional (2D) systems. One consequence of the theory is that there is no quantum percolation transition in 2D. However, in a real system…
The interplay between strong Coulomb interactions and randomness has been a long-standing problem in condensed matter physics. According to the scaling theory of localization, in two-dimensional systems of noninteracting or weakly…
We propose a scaling theory of 2D metal insulator transition discovered by Kravchenko and coworkers. In this theory conductance/resistance duality is an exact relation. The exponent of the stretched exponential in $\sigma(T)$ is determined…
In recent years systematic experimental studies of the temperature dependence of the resistivity in a variety of dilute, ultra clean two dimensional electron/hole systems have revived the fundamental question of localization or,…
We argue on the basis of experimental numbers that the B=0 metal-insulator transition in two dimensions, observed in Si-MOSFETs and in other two-dimensional systems, is likely to be due to a few strongly interacting electrons, which also…