Three decades after the prediction of charge-vortex duality in the critical vicinity of the two-dimensional superconductor-insulator transition (SIT), one of the fundamental implications of this duality-the charge Berezinskii-Kosterlitz-Thouless (BKT) transition that should occur on the insulating side of the SIT-has remained unobserved. The dual picture of the process points to the existence of a superinsulating state endowed with zero conductance at finite temperature. Here, we report the observation of the charge BKT transition on the insulating side of the SIT in 10 nm thick NbTiN films, identified by the BKT critical behavior of the temperature and magnetic field dependent resistance, and map out the magnetic-field dependence of the critical temperature of the charge BKT transition. Finally, we ascertain the effects of the finite electrostatic screening length and its divergence at the magnetic field-tuned approach to the superconductor-insulator transition.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840303 | PMC |
http://dx.doi.org/10.1038/s41598-018-22451-1 | DOI Listing |
Phys Rev Lett
December 2024
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
The crystallographic restriction theorem constrains two-dimensional nematicity to display either Ising (Z_{2}) or three-state-Potts (Z_{3}) critical behaviors, both of which are dominated by amplitude fluctuations. Here, we use group theory and microscopic modeling to show that this constraint is circumvented in a 30°-twisted hexagonal bilayer due to its emergent quasicrystalline symmetries. We find a critical phase dominated by phase fluctuations of a Z_{6} nematic order parameter and bounded by two Berezinskii-Kosterlitz-Thouless (BKT) transitions, which displays only quasi-long-range nematic order.
View Article and Find Full Text PDFSci Rep
November 2024
Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka, 816-8580, Japan.
Kinetic roughening of the (001) singular surface during steady crystal growth is studied on the basis of a lattice model using the Monte Carlo method. At a sufficiently low temperature, there are known to be two kinetic roughening points as the driving force for crystal growth increases. At a low driving force , there is the Karder-Parisi-Zhang (KPZ) roughening transition point.
View Article and Find Full Text PDFEntropy (Basel)
October 2024
Department of Theoretical Physics and Astrophysics, Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University in Košice, Park Angelinum 9, 041 54 Košice, Slovakia.
We propose spin models that can display an arbitrary number of phase transitions. The models are based on the standard XY model, which is generalized by including higher-order nematic terms with exponentially increasing order and linearly increasing interaction strength. By employing Monte Carlo simulation we demonstrate that under certain conditions the number of phase transitions in such models is equal to the number of terms in the generalized Hamiltonian and, thus, it can be predetermined by construction.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
November 2024
Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic.
Phys Rev Lett
September 2024
School of Physics, Beijing Institute of Technology, Beijing 100081, China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!