TY - JOUR
T1 - Vortex-induced quantum metallicity in the mono-unit-layer superconductor NbS e2
AU - Ichinokura, Satoru
AU - Nakata, Yuki
AU - Sugawara, Katsuaki
AU - Endo, Yukihiro
AU - Takayama, Akari
AU - Takahashi, Takashi
AU - Hasegawa, Shuji
PY - 2019/6/5
Y1 - 2019/6/5
N2 - We performed in situ magnetoresistance measurements in the ultrahigh-vacuum environment to reveal the quantum phase transitions of single unit-layer NbSe2 epitaxially grown on bilayer graphene. It was found that the superconductor-normal state transition caused by the surface-normal magnetic field was intermediated by a quasimetallic state. This behavior is consistent with the "Bose metal" picture where a finite dissipation is caused by the breaking of phase coherence due to strong gauge-field fluctuation. On one hand, around the mean-field critical temperature, the onset of transition from the normal state to the low-temperature states was governed by the amplitude-fluctuation effect, prominently under the magnetic field. We applied scaling theories to determine the phase boundaries. The result of scaling analyses revealed a complex but essential phase diagram of the single unit-layer NbSe2 as a two-dimensional superconductor.
AB - We performed in situ magnetoresistance measurements in the ultrahigh-vacuum environment to reveal the quantum phase transitions of single unit-layer NbSe2 epitaxially grown on bilayer graphene. It was found that the superconductor-normal state transition caused by the surface-normal magnetic field was intermediated by a quasimetallic state. This behavior is consistent with the "Bose metal" picture where a finite dissipation is caused by the breaking of phase coherence due to strong gauge-field fluctuation. On one hand, around the mean-field critical temperature, the onset of transition from the normal state to the low-temperature states was governed by the amplitude-fluctuation effect, prominently under the magnetic field. We applied scaling theories to determine the phase boundaries. The result of scaling analyses revealed a complex but essential phase diagram of the single unit-layer NbSe2 as a two-dimensional superconductor.
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U2 - 10.1103/PhysRevB.99.220501
DO - 10.1103/PhysRevB.99.220501
M3 - Article
AN - SCOPUS:85067194660
VL - 99
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 2469-9950
IS - 22
M1 - 220501
ER -