Z.F. Ezawa
Tohoku University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Z.F. Ezawa.
Physical Review Letters | 1998
A. Sawada; Z.F. Ezawa; Hideo Ohno; Yoshiji Horikoshi; Y. Ohno; S. Kishimoto; F. Matsukura; M. Yasumoto; A. Urayama
The Hall-plateau width and the activation energy were measured in the bilayer quantum Hall state at filling factor \nu=2, 1 and 2/3, by changing the total electron density and the density ratio in the two quantum wells. Their behavior are remarkably different from one to another. The \nu=1 state is found stable over all measured range of the density difference, while the \nu=2/3
International Journal of Modern Physics B | 1992
Z.F. Ezawa; Aiichi Iwazaki
state is stable only around the balanced point. The \nu=2 state, on the other hand, shows a phase transition between these two types of the states as the electron density is changed.
Physical Review B | 1999
A. Sawada; Z.F. Ezawa; Hideo Ohno; Yoshiji Horikoshi; A. Urayama; Y. Ohno; S. Kishimoto; F. Matsukura; Norio Kumada
We present a microscopic theory of the fractional quantum Hall effect at the filling factor ν with even denominator, which is recently observed in a double-layer electron system. In our approach electrons belonging to different layers are interpreted as different types of anyons with appropriate statistics. The wavefunction of the Hall state is calculated, which is found to coincide with that of Halperin. We also analyze vortex (quasihole) excitations. It is shown that a single vortex carries electric charges on both of the layers; for instance, a vortex at ν=½ has the electric charge on one layer and -⅛e on the other layer. The ground state at the vicinity of ν=½ is given by a Wigner crystal made of these vortices.
Reports on Progress in Physics | 2009
Z.F. Ezawa; G. Tsitsishvili
We have measured the Hall-plateau width and the activation energy of the bilayer quantum Hall (BLQH) states at the Landau-level filling factor
Physical Review Letters | 1999
Z.F. Ezawa
\nu=1
Physical Review B | 2003
Z.F. Ezawa; G. Tsitsishvili; K. Hasebe
and 2 by tilting the sample and simultaneously changing the electron density in each quantum well. The phase transition between the commensurate and incommensurate states are confirmed at
Solid State Communications | 1999
K. Muraki; Tadashi Saku; Yoshiro Hirayama; Norio Kumada; A. Sawada; Z.F. Ezawa
\nu =1
Physics Letters B | 1989
Ursula Carow-Watamura; Z.F. Ezawa; Kuni Harada; A. Tezuka; Satoshi Watamura
and discovered at
Physical Review B | 2002
Z.F. Ezawa; K. Hasebe
\nu =2
Physica E-low-dimensional Systems & Nanostructures | 2004
D. Terasawa; Masayuki Morino; K. Nakada; S. Kozumi; A. Sawada; Z.F. Ezawa; Norio Kumada; K. Muraki; Tadashi Saku; Yoshiro Hirayama
. In particular, three different