TY - JOUR
T1 - Randomly Hopping Majorana Fermions in the Diluted Kitaev System α - Ru0.8Ir0.2Cl3
AU - Do, Seung Hwan
AU - Lee, C. H.
AU - Kihara, Takumi
AU - Choi, Y. S.
AU - Yoon, Sungwon
AU - Kim, Kangwon
AU - Cheong, Hyeonsik
AU - Chen, Wei Tin
AU - Chou, Fangcheng
AU - Nojiri, H.
AU - Choi, Kwang Yong
N1 - Funding Information:
This work was supported by National Research Foundation (KRF) Grants (No. 2017R1A2B3012642 and No. 2019R1A2C3006189) funded by the Korea government Ministry of Science and ICT (MSIT) as well as by ICC-IMR (Institute for Materials Research), Tohoku University. Part of this work has been supported by GIMRT program of IMR (No. 18H0078 and 19H0504). H. N. acknowledges KAKEH18H 04300.
Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/1/31
Y1 - 2020/1/31
N2 - dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru1-xIrxCl3 (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (â.,ω>3 meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.
AB - dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru1-xIrxCl3 (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (â.,ω>3 meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.
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U2 - 10.1103/PhysRevLett.124.047204
DO - 10.1103/PhysRevLett.124.047204
M3 - Article
C2 - 32058744
AN - SCOPUS:85079560019
SN - 0031-9007
VL - 124
JO - Physical Review Letters
JF - Physical Review Letters
IS - 4
M1 - 047204
ER -