2020/06/30 by Sambuddha Sanyal, S. Sanyal, K. Damle +4
Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Excited state #MAJORANA #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Quantum spin liquid #Singlet state #Spin (aerodynamics) #Spin polarization #Spins #Superconductivity #Thermodynamics #Vacancy defect #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.127.127201
published as Phys. Rev. Lett. 127, 127201 (2021) · two-column format; 4+pages; 3 figures
arxiv created 2020/06/30 · openalex publication_date 2021/09/13 · arxiv updated 2021/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We exhibit an exactly solvable example of a SU(2) symmetric Majorana spin liquid phase, in which quenched disorder leads to random-singlet phenomenology of emergent magnetic moments. More precisely, we argue that a strong-disorder fixed point controls the low temperature susceptibility χ(T) of an exactly solvable S=1/2 model on the decorated honeycomb lattice with vacancy and/or bond disorder, leading to χ(T)=C/T+DTα(T)-1, where α(T)→0 slowly as the temperature T→0. The first term is a Curie tail that represents the emergent response of vacancy-induced spin textures spread over many unit cells: it is an intrinsic feature of the site-diluted system, rather than an extraneous effect arising from isolated free spins. The second term, common to both vacancy and bond disorder [with different α(T) in the two cases] is the response of a random singlet phase, familiar from random antiferromagnetic spin chains and the analogous regime in phosphorus-doped silicon (Si:P).