Partial Disordered Phase of Ising Spin System in Distorted Triangular Lattice RbCoBr<sub>3</sub>

Nishiwaki, Yasushi; Nakamura, Tota; Oosawa, Akira; Kakurai, Kazuhisa; Todoroki, Norikazu; Igawa, Naoki; Ishii, Yoshinobu; Kato, T.

doi:10.1143/jpsj.77.104703

Cited by 22 publications

(23 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This spin configuration, which is illustrated in Fig. 6 and sets the magnetic space group P6 3 /m cm indicated in Table V, has also been deduced for the AFM1 phases of all the most closely related ACoX 3 systems, namely, CsCoCl 3 [45,75], CsCoBr 3 [46], and RbCoBr 3 [43].…”

Section: Afm1 Structure Below T N1supporting

confidence: 64%

“…Only the Co 2+ compounds show ordered moments exclusively along the z direction, which is a consequence of their pronounced Ising anisotropy. The reported ordered moments range from 2.7 to 3.1μ B [43][44][45][46], and for RbCoCl 3 we have found a rather similar value of μ z = √ 3μ z0 /2 = 3.22(7)μ B , while μ z0 = 3.72(8)μ B approaches the spin-only value for high-spin Co 2+ , √ 15μ B ≈ 3.87μ B .…”

Section: Phase K-vectorsupporting

confidence: 60%

“…CsFeCl 3 (d 6 ) has a singlet ground state and shows magnetic order only in an external field (H||c > 4 T); uniquely, this compound has a FM coupling along the c axis [40,41]. Finally, among the Co 2+ compounds (d 7 ) TlCoCl 3 has KNiCl 3 -type lattice distortions [42], RbCoBr 3 shows a weak distortion only at the onset of magnetic order [43], and CsCoCl 3 [44,45] and CsCoBr 3 [46] maintain their higher structural symmetry to the lowest temperatures while, in common with RbCoBr 3 , exhibiting two successive magnetic phase transitions.…”

Section: Magnetic Structurementioning

confidence: 99%

See 2 more Smart Citations

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

et al. 2021

View full text Add to dashboard Cite

In RbCoCl 3 , the magnetic Co 2+ ions form weakly coupled Ising chains arranged on a triangular lattice. We have investigated the structure and magnetism in RbCoCl 3 by high-resolution x-ray diffraction and neutron scattering measurements on powder and single-crystal samples between 1.5 and 300 K. Upon cooling, the Co 2+ spins develop one-dimensional antiferromagnetic correlations along the chain axis (c axis) below 90 K. Below the first Néel temperature, T N1 = 28 K, a partial three-dimensional magnetic order sets in, with propagation vector k 1 = (1/3, 1/3, 1), the moments aligned along the c axis, and every third chain uncorrelated from its neighbors. Only below a second magnetic phase transition at T N2 = 13 K does the system achieve a fully ordered state, with two additional propagation vectors: k 2 = (0, 0, 1) establishes a "honeycomb" c-axis order, in which one third of the chains are subject to a strong effective mean field due to their neighbors whereas two thirds experience no net field, while k 3 = (1/2, 0, 1) governs a small, staggered, in-plane ordered moment. We conclude that RbCoCl 3 is an excellent material to study the physics of Ising chains in a wide variety of temperature-controlled environments, and our results build an important foundation for the accurate interpretation of the spin dynamics measured in each case.

show abstract

Section: Afm1 Structure Below T N1supporting

confidence: 64%

Section: Phase K-vectorsupporting

confidence: 60%

Section: Magnetic Structurementioning

confidence: 99%

See 1 more Smart Citation

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Related stacked triangular lattice XYantiferromagnets have been extensively studied in the context of the magnetic properties of hexagonal ABX 3 compounds with space group P 6 3 cm 12,19,30 .…”

Section: Fig 1: (Color Online)mentioning

confidence: 99%

Correlated Partial Disorder in a Weakly Frustrated Quantum Antiferromagnet

et al. 2019

View full text Add to dashboard Cite

Partial disorder -the microscopic coexistence of long-range magnetic order and disorder-is a rare phenomenon, that has been experimental and theoretically reported in some Ising-or easy planespin systems, driven by entropic effects at finite temperatures. Here, we present an analytical and numerical analysis of the S = 1/2 Heisenberg antiferromagnet on the √ 3 × √ 3-distorted triangular lattice, which shows that its quantum ground state has partial disorder in the weakly frustrated regime. This state has a 180 • Néel ordered honeycomb subsystem, coexisting with disordered spins at the hexagon center sites. These central spins are ferromagnetically aligned at short distances, as a consequence of a Casimir-like effect originated by the zero-point quantum fluctuations of the honeycomb lattice.Introduction-Zero-point quantum fluctuations in condensed systems are responsible for a wide variety of interesting phenomena, ranging from the existence of liquid helium near zero temperature to magnetically disordered Mott insulators 1,2 . It is in the quantum magnetism arena, precisely, where a plethora of control factors are available for tuning the amount of quantum fluctuations. Among these factors, space dimensionality, lattice coordination number, spin value S, and frustrating exchange interactions are the most relevant 3,4 .While folk wisdom visualizes zero-point quantum fluctuations like a uniform foam resulting from an almost random sum of states, in some cases these fluctuations contribute to the existence of very unique phenomena. These phenomena include semiclassical orders 3 , order by disorder 5 , effective dimensionality reduction 6,7 , and topological orders associated with quantum spin liquid states 1 , among others. Another role for quantum fluctuations is to allow the emergence of complex degrees of freedom from the original spins, like weakly coupled clusters or active spin sublattices decoupled from orphan spins. The latter has been proposed to explain the spin liquid behavior of the LiZn 2 Mo 3 O 8 8 . Here the system is described by a triangular spin-1 2 Heisenberg antiferromagnet which is deformed into an emergent honeycomb lattice weakly coupled to the central spins.Besides spin liquids, the presence of weakly coupled magnetic subsystems can lead to partial disorder, that is, the microscopic coexistence of long-range magnetic order and disorder. This rare phenomenon has been experimental and theoretically reported in different localized or itinerant Ising-or XY-spin highly frustrated systems 9-25 and it is driven by entropic effects at finite temperature. In general, it is believed that some amount of spin anisotropy is needed to get partial disorder, and that the disordered subsystem behaves as a perfect paramagnet, with its decoupled spins justifying then the calificative of orphan spins.In this work, we present an isotropic frustrated magnetic system whose ground state exhibits partial disorder, originated by zero-point quantum effects, in contrast to the entropic origin of the so-far known cases. ...

show abstract

“…Such a reentrant phenomenon was experimentally confirmed 2 , and theoretically investigated with different approaches 1,[3][4][5][6][7][8] . In the past decades, systematic investigations on the partially disordered phase in both classical and quantum systems at finite temperatures were performed theoretically 1,4,5,[9][10][11][12][13][14][15] and experimentally [16][17][18][19][20][21] . It has been widely recognized that the partially disordered phase is driven by the thermal entropy, in which the disordered part behaves like a "perfect" paramagnet.…”

mentioning

confidence: 99%

Reentrance of the topological phase in a spin-1 frustrated Heisenberg chain

et al. 2020

View full text Add to dashboard Cite

For the Haldane phase, the magnetic field usually tends to break the symmetry and drives the system into a topologically trivial phase. Here, we report a novel reentrance of the Haldane phase at zero temperature in the spin-1 antiferromagnetic Heisenberg model on sawtooth chain. A partial Haldane phase is induced by the magnetic field, which is the combination of the Haldane state in one sublattice and a ferromagnetically ordered state in the other sublattice. Such a partial topological order is a result of the zero-temperature entropy due to quantum fluctuations caused by geometrical frustration.Introduction. -Frustration incorporating with strong correlations usually leads to exotic quantum phenomena. A typical example in statistical physics is the reentrant phenomena, where a sequence of phase transitions, such as A-B-A-B by lowering temperature may happen, where A and B denote ordered and disordered phases, respectively. Taking the Ising model on kagomé lattice with nearest and next-nearest neighboring interactions as an example, one may find that upon lowering temperature, the system passes through four phases, a paramagnetic phase, a magnetically-ordered phase, a reentrant paramagnetic phase, and a ferromagnetic phase 1 . Such a reentrant phenomenon was experimentally confirmed 2 , and theoretically investigated with different approaches 1,3-8 . In the past decades, systematic investigations on the partially disordered phase in both classical and quantum systems at finite temperatures were performed theoretically 1,4,5,[9][10][11][12][13][14][15] and experimentally [16][17][18][19][20][21] . It has been widely recognized that the partially disordered phase is driven by the thermal entropy, in which the disordered part behaves like a "perfect" paramagnet. The reentrant phenomena can be viewed as the order-bydisorder effect 22 , which is driven by thermal fluctuations and entropy.Recently, the interests on the reentrant phenomena were renewed. The order-by-disorder effects were investigated theoretically 23-26 and experimentally 27,28 . For the spin-1/2 Heisenberg antiferromagnet on the √ 3 × √ 3disordered triangular lattice 26 , a partially disordered ground state in the weakly frustrated regime was reported. The spins on the honeycomb sublattice form a 180 • Néel order, and spins at the hexagon center sites are in a disordered state. This work is aimed at explaining the spin-liquid behaviors of LiZn 2 M o 3 O 8 29 , and shows that a partially disordered phase can be the ground state of a simple quantum isotropic Heisenberg antiferromagnet. Comparing with the classical systems, the disordered subsystem is a short range ferromagnetically correlated state instead of a paramagnet, and the mechanism is owning to the zero-point quantum fluctuations instead of the thermal ones. Furthermore, previous works 1 J 2 J : Sublattice A : Sublattice B FIG. 1. (Color online) Sawtooth chain lattice with two sublattice A and B. Two exchange interactions J1 and J2 are indicated by black and green lines, respectively.show that ...

show abstract

Partial Disordered Phase of Ising Spin System in Distorted Triangular Lattice RbCoBr₃

Cited by 22 publications

References 45 publications

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

Correlated Partial Disorder in a Weakly Frustrated Quantum Antiferromagnet

Reentrance of the topological phase in a spin-1 frustrated Heisenberg chain

Contact Info

Product

Resources

About

Partial Disordered Phase of Ising Spin System in Distorted Triangular Lattice RbCoBr3

Cited by 22 publications

References 45 publications

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

Magnetic order in the quasi-one-dimensional Ising system RbCoCl3

Correlated Partial Disorder in a Weakly Frustrated Quantum Antiferromagnet

Reentrance of the topological phase in a spin-1 frustrated Heisenberg chain

Contact Info

Product

Resources

About

Partial Disordered Phase of Ising Spin System in Distorted Triangular Lattice RbCoBr₃