@article{dc70b9fe077544938fade0363ed3ca40,
title = "Observation of in-plane magnetic field induced phase transitions in FeSe",
abstract = "We investigate thermodynamic properties of FeSe under in-plane magnetic fields using torque magnetometry, specific heat, and magnetocaloric measurements. Below the upper critical field Hc2, we observed the field induced anomalies at H1∼15 T and H2∼22 T near H{\^a}ˆ1ab and below a characteristic temperature T∗∼ 2 K. The transition magnetic fields H1 and H2 exhibit negligible dependence on both temperature and field orientation. This contrasts to the strong temperature and angle dependence of Hc2, suggesting that these anomalies are attributed to the field induced phase transitions, originating from the inherent spin-density-wave instability of quasipaticles near the superconducting gap minima or possible Flude-Ferrell-Larkin-Ovchinnikov state in the highly spin-polarized Fermi surfaces. Our observations imply that FeSe, an atypical multiband superconductor with extremely small Fermi energies, represents a unique model system for stabilizing unusual superconducting orders beyond the Pauli limit.",
author = "Ok, {Jong Mok} and Kwon, {Chang Il} and Yoshimitsu Kohama and You, {Jung Sang} and Park, {Sun Kyu} and Kim, {Ji Hye} and Jo, {Y. J.} and Choi, {E. S.} and Koichi Kindo and Woun Kang and Kim, {Ki Seok} and Moon, {E. G.} and A. Gurevich and Kim, {Jun Sung}",
note = "Funding Information: The authors thank Y. Matsuda and D. J. Jang for fruitful discussion. We also thank H. G. Kim in Pohang Accelerator Laboratory (PAL) for the technical support. This work was supported by the Institute for Basic Science (IBS) through the Center for Artificial Low Dimensional Electronic Systems (Grant No. IBS-R014-D1) and also by the National Research Foundation of Korea (NRF) through SRC (Grant No. 2018R1A5A6075964) and the Max Planck-POSTECH Center for Complex Phase Materials (Grant No. 2016K1A4A4A01922028). W.K. acknowledges the support by NRF (Grants No. 2018R1D1A1B07050087 and No. 2018R1A6A1A03025340), and Y.J.J. was supported by NRF (Grant No. 2016R1A2B4016656). E.-G. M. was supported by NRF of Korea under Grants No. NRF-2017R1C1B2009176 and No. NRF-2019M3E4A1080411. Publisher Copyright: {\textcopyright} 2020 American Physical Society.",
year = "2020",
month = jun,
day = "1",
doi = "10.1103/PhysRevB.101.224509",
language = "English",
volume = "101",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "22",
}