Coulomb interaction among transporting charge carriers confined in two dimensions

2008 ◽  
Vol 104 (8) ◽  
pp. 083716 ◽  
Author(s):  
G. H. Buh ◽  
Ji-Yong Park ◽  
Young Kuk
2008 ◽  
Vol 22 (15) ◽  
pp. 2473-2487 ◽  
Author(s):  
HANA ČENČARIKOVÁ ◽  
PAVOL FARKAŠOVSKÝ ◽  
MARTIN ŽONDA

A combination of small-cluster exact diagonalizations and a well-controlled approximative method is used to study the ground states of the Falicov–Kimball model extended by nonlocal Coulomb interaction (U non ). It is shown that the ground-state phase diagram as well as the picture of valence and metal–insulator transitions found for the conventional Falicov–Kimball model are strongly changed when the nonlocal Coulomb interaction is added. This is illustrated for three selected values of the on-site Coulomb interaction (U) that represent typical behaviors of the model for small, intermediate and strong interactions. A number of remarkable results are found: (i) the phase separation takes place for a wide range of U non in all three interaction limits; (ii) in the weak and intermediate coupling limit, the model exhibits the nonlocal Coulomb interaction–induced insulator–metal transition; (iii) depending on the value of U non , the model is able to describe both the continuous and the discontinuous changes of the f-electron occupation number; (iv) new types of inhomogeneous charge ordering (including various types of axial and diagonal stripes) are observed for nonzero U non .


2015 ◽  
Vol 119 (10) ◽  
pp. 5364-5373 ◽  
Author(s):  
Yohichi Suzuki ◽  
Akihiro Furube ◽  
Rupashree Balia Singh ◽  
Hiroyuki Matsuzaki ◽  
Tsutomu Minegishi ◽  
...  

2017 ◽  
Vol 51 (5) ◽  
pp. 565-570 ◽  
Author(s):  
N. N. Ageeva ◽  
I. L. Bronevoi ◽  
D. N. Zabegaev ◽  
A. N. Krivonosov

2006 ◽  
Vol 3 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Kia Manouchehri ◽  
J. B. Wang

To study the ballistic transport of charge carriers in nano-structured quantum devices, a highly efficient numerical technique is developed, which provides continuous transmission spectra for arbitrarily complex potential geometries in two dimensions. We apply the proposed method to single and double barrier structures and compare the results with those obtained using standard techniques for computing transmission coefficients. Excellent numerical agreement as well as considerable computational saving is demonstrated.


JETP Letters ◽  
1999 ◽  
Vol 69 (10) ◽  
pp. 753-761 ◽  
Author(s):  
É. A. Pashitskii ◽  
V. I. Pentegov ◽  
A. V. Semenov ◽  
E. Abraham

2009 ◽  
Vol 23 (20n21) ◽  
pp. 4198-4215 ◽  
Author(s):  
M. SAARELA ◽  
F. V. KUSMARTSEV

We study properties of charge fluids with random impurities or heavy polarons using a microscopic Hamiltonian with the full many-body Coulomb interaction. At zero temperature and high enough density the bosonic fluid is superconducting, but when density decreases the Coulomb interaction will be strongly over-screened and impurities or polarons begin to trap charge carriers forming bound quasiparticle like clusters, which we call Coulomb bubbles or clumps. These bubbles are embedded inside the superconductor and form nuclei of a new insulating state. The growth of a bubble is terminated by the Coulomb force. The fluid contains two groups of charge carriers associated with free and localized states. The insulating state arises via a percolation of the insulating islands of bubbles, which cluster and prevent the flow of the electrical supercurrent through the system. Our results are applicable to HTSC. There the Coulomb fluids discussed in the paper correspond to mobile holes located on Cu sites and heavy polarons or charged impurities located on Oxygen sites. As a result of our calculations the following two-componet picture of two competing orders in cuprates arise. The mobile and localized states are competing with each other and their balance is controlled by doping. At high doping a large Fermi surface is open. There the density of real charge carriers is significantly larger than the density of the doped ones. When doping decreases more and more carriers are localized as Coulomb clumps which are creating around heavy polarons localized on Oxygen sites and forming a regular lattice. The picture is consistent with the Gorkov and Teitelbaum (GT) analysis 1,2 of the transport, Hall effect data and the ARPES spectra as well as with nanoscale superstructures observed in Scanning Tunneling Microscope(STM) experiments [3-8]. The scenario of the clump formation may be also applicable to pnictides, where two types of clumps may arise even at very high temperatures.


Sign in / Sign up

Export Citation Format

Share Document