Quantum fluctuations from frustration can trigger quantum spin liquids (QSLs) at zero temperature. However, it is unclear how thermal fluctuations affect a QSL. We employ state-of-the-art tensor network-based methods to explore the spin- $1/2$ kagom\'e Heisenberg antiferromagnet (KHA). Its ground state is shown to be a gapless U(1) QSL. By studying the behaviors of specific heat and magnetic susceptibility, we propose a finite-temperature phase diagram for the spin-1/2 KHA in a magnetic field. It is unveiled that there exists an algebraic paramagnetic liquid (APL) that possesses both paramagnetic and algebraic behaviors inherited from the QSL. The APL is induced under the interplay between quantum fluctuations from geometrical frustration and thermal fluctuations. Our work suggests that even when the QSL at zero temperature is frozen into a solid state by a magnetic field, proper thermal fluctuations could melt the system into a liquid-like state. We speculate that an APL phase could generally emerge after proper thermal fluctuations intervene in a gapless QSL.Quantum fluctuations from frustration can trigger quantum spin liquids (QSLs) at zero temperature. However, it is unclear how thermal fluctuations affect a QSL. We employ state-of-the-art tensor network-based methods to explore the spin-$1/2$ kagom\'e Heisenberg antiferromagnet (KHA). Its ground state is shown to be a gapless U(1) QSL. By studying the behaviors of specific heat and magnetic susceptibility, we propose a finite-temperature phase diagram for the spin-1/2 KHA in a magnetic field. It is unveiled that there exists an algebraic paramagnetic liquid (APL) that possesses both paramagnetic and algebraic behaviors inherited from the QSL. The APL is induced under the interplay between quantum fluctuations from geometrical frustration and thermal fluctuations. Our work suggests that even when the QSL at zero temperature is frozen into a solid state by a magnetic field, proper thermal fluctuations could melt the system into a liquid-like state. We speculate that an APL phase could generally emerge after proper thermal fluctuations intervene in a gapless QSL.

Nov 3, 20171 citation

The ground state of the 1/5-doped antiferromagntic spin chain

Yongjun Liu

By density-matrix renormalization group method,the 1/5-doping effect on the spin-1/2 Heisenberg antiferromagnetic chain is investigated.It is shown that adding side spins can weaken the correlations between near-neighbor spins while strengthen those between long-range spins.Because of the broken of sublattice symmetry by side spins,the ferromagnetic and the antiferromagnetic long range orders can coexist in the ground state.Side spins can lower the quantum fluctuations,and the effect will weaken as the increasing of interaction distance.The quantum fluctuation of side spin is weakest.But for the 1/5-doped antiferromagntic chain,the quantum fluctuation leads to the 47% loss of its staggered susceptibility.By density-matrix renormalization group method,the 1/5-doping effect on the spin-1/2 Heisenberg antiferromagnetic chain is investigated.It is shown that adding side spins can weaken the correlations between near-neighbor spins while strengthen those between long-range spins.Because of the broken of sublattice symmetry by side spins,the ferromagnetic and the antiferromagnetic long range orders can coexist in the ground state.Side spins can lower the quantum fluctuations,and the effect will weaken as the increasing of interaction distance.The quantum fluctuation of side spin is weakest.But for the 1/5-doped antiferromagntic chain,the quantum fluctuation leads to the 47% loss of its staggered susceptibility.

Journal of Yangzhou UniversityJan 1, 20090 citations

Quantum antiferromagnets with competing interactions

Stavros Thanos, P.N. Moustanis

Physica A Statistical Mechanics and its ApplicationsSep 1, 199910 citations

1/2

kagom\'e Heisenberg antiferromagnet (KHA). Its ground state is shown to be a gapless U(1) QSL. By studying the behaviors of specific heat and magnetic susceptibility, we propose a finite-temperature phase diagram for the spin-1/2 KHA in a magnetic field. It is unveiled that there exists an algebraic paramagnetic liquid (APL) that possesses both paramagnetic and algebraic behaviors inherited from the QSL. The APL is induced under the interplay between quantum fluctuations from geometrical frustration and thermal fluctuations. Our work suggests that even when the QSL at zero temperature is frozen into a solid state by a magnetic field, proper thermal fluctuations could melt the system into a liquid-like state. We speculate that an APL phase could generally emerge after proper thermal fluctuations intervene in a gapless QSL.