Abstract
Ground state of the two-dimensional hard-core-boson model subjected to external magnetic field and quenched random chemical potential is studied numerically. In experiments, magnetic-field-tuned superconductor-insulator transition has already come under through investigation, whereas in computer simulation, only randomness-driven localization (with zero magnetic field) has been studied so far: The external magnetic field brings about a difficulty that the hopping amplitude becomes complex number (through the gauge twist), for which the quantum Monte-Carlo simulation fails. Here, we employ the exact diagonalization method, with which we demonstrate that the model does exhibit field-tuned localization transition at a certain critical magnetic field. At the critical point, we found that the DC conductivity is not universal, but is substantially larger than that of the randomness-driven localization transition at zero magnetic field. Our result supports recent experiment by Marković et al. reporting an increase of the critical conductivity with magnetic field strengthened.
| Original language | English |
|---|---|
| Pages (from-to) | 147-155 |
| Number of pages | 9 |
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 353 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - May 1 2001 |
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Keywords
- Critical conductivity
- Dynamical critical exponent
- Exact-diagonalization method
- Finite-size-scaling method
- Randomness
- Superconductor-insulator transition
ASJC Scopus subject areas
- Condensed Matter Physics
Cite this
Numerical analysis of the magnetic-field-tuned superconductor-insulator transition in two dimensions. / Nishiyama, Yoshihiro.
In: Physica C: Superconductivity and its Applications, Vol. 353, No. 1-2, 01.05.2001, p. 147-155.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Numerical analysis of the magnetic-field-tuned superconductor-insulator transition in two dimensions
AU - Nishiyama, Yoshihiro
PY - 2001/5/1
Y1 - 2001/5/1
N2 - Ground state of the two-dimensional hard-core-boson model subjected to external magnetic field and quenched random chemical potential is studied numerically. In experiments, magnetic-field-tuned superconductor-insulator transition has already come under through investigation, whereas in computer simulation, only randomness-driven localization (with zero magnetic field) has been studied so far: The external magnetic field brings about a difficulty that the hopping amplitude becomes complex number (through the gauge twist), for which the quantum Monte-Carlo simulation fails. Here, we employ the exact diagonalization method, with which we demonstrate that the model does exhibit field-tuned localization transition at a certain critical magnetic field. At the critical point, we found that the DC conductivity is not universal, but is substantially larger than that of the randomness-driven localization transition at zero magnetic field. Our result supports recent experiment by Marković et al. reporting an increase of the critical conductivity with magnetic field strengthened.
AB - Ground state of the two-dimensional hard-core-boson model subjected to external magnetic field and quenched random chemical potential is studied numerically. In experiments, magnetic-field-tuned superconductor-insulator transition has already come under through investigation, whereas in computer simulation, only randomness-driven localization (with zero magnetic field) has been studied so far: The external magnetic field brings about a difficulty that the hopping amplitude becomes complex number (through the gauge twist), for which the quantum Monte-Carlo simulation fails. Here, we employ the exact diagonalization method, with which we demonstrate that the model does exhibit field-tuned localization transition at a certain critical magnetic field. At the critical point, we found that the DC conductivity is not universal, but is substantially larger than that of the randomness-driven localization transition at zero magnetic field. Our result supports recent experiment by Marković et al. reporting an increase of the critical conductivity with magnetic field strengthened.
KW - Critical conductivity
KW - Dynamical critical exponent
KW - Exact-diagonalization method
KW - Finite-size-scaling method
KW - Randomness
KW - Superconductor-insulator transition
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UR - http://www.scopus.com/inward/citedby.url?scp=0035337079&partnerID=8YFLogxK
U2 - 10.1016/S0921-4534(00)01741-X
DO - 10.1016/S0921-4534(00)01741-X
M3 - Article
VL - 353
SP - 147
EP - 155
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -