Dynamics of Composite Haldane Spin Chains in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>IPA</mml:mi><mml:mtext mathvariant="normal">−</mml:mtext><mml:msub><mml:mi>CuCl</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>

Masuda, Takatsugu; Zheludev, A.; Manaka, Hirotaka; Regnault, L.P.; Chung, Jaiho; Qiu, Yiming

doi:10.1103/physrevlett.96.047210

Cited by 134 publications

(159 citation statements)

References 21 publications

Supporting

Mentioning

151

Contrasting

Order By: Relevance

“…1, spontaneous (T = 0) decay of a magnon into a pair of quasiparticles becomes possible, which leads to a rapid decrease in the quasiparticle life-time in the former case 5 and complete disappearance of the single-particle branch in the latter system. 6 Quasiparticle instability is well documented for another type of quantum liquid-superfluid 4 He. Predicted by Pitaevskii nearly fifty years ago, 7,8,9 this instability was later confirmed by neutron scattering measurements.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Decay of quasiparticles in quantum spin liquids

Zhitomirsky

2006

Phys. Rev. B

View full text Add to dashboard Cite

Magnetic excitations are studied in gapped quantum spin systems, for which spontaneous twomagnon decays are allowed by symmetry. Interaction between one-and two-particle states acquires nonanalytic frequency and momentum dependence near the boundary of two-magnon continuum. This leads to a termination point of single-particle branch for one-dimensional systems and to strong suppression of quasiparticle weight in two dimensions. The momentum dependence of the decay rate is calculated in arbitrary dimensions and effect of external magnetic field is discussed.PACS numbers: 75.10. Jm, 75.10.Pq, 78.70.Nx A number of magnetic materials with quantum disordered, or spin-liquid, ground states have been discovered in the past two decades. The well-known examples include the spin-Peierls compound CuGeO 3 , 1 dimer systems Cs 3 Cr 2 Br 9 2 and TlCuCl 3 , 3 integer-spin antiferromagnetic chains, 4 and many others. Common property of all these systems is presence of a spin gap in the excitation spectrum, which separates a singlet, S = 0 ground state from S = 1 quasiparticles. The lowenergy triplet of magnons can be split due to intrinsic anisotropies or under applied magnetic field. Recent neutron experiments 5,6 on two organic spin-gap materials PHCC and IPA-CuCl 3 have revealed drastic transformation of triplet quasiparticles undergoing at high energies. Upon entering two-magnon continuum, see Fig. 1, spontaneous (T = 0) decay of a magnon into a pair of quasiparticles becomes possible, which leads to a rapid decrease in the quasiparticle life-time in the former case 5 and complete disappearance of the single-particle branch in the latter system. 6 Quasiparticle instability is well documented for another type of quantum liquid-superfluid 4 He. Predicted by Pitaevskii nearly fifty years ago, 7,8,9 this instability was later confirmed by neutron scattering measurements. 10,11 In liquid helium, interaction between one-and two-particle states is enhanced in the vicinity of a decay threshold by a large density of roton states and leads to avoided crossing: the single-particle branch flattens at energies below twice the roton energy and ceases to exist completely above that energy scale.The aim of present article is to investigate similar effects in quantum spin liquids. We consider an isotropic spin system with a quantum disordered ground state, which is separated by a finite gap ∆ from low-energy spin-1 excitations. A bare dispersion of propagating triplets is given by ε(p). Bosonic operators t pα and t † pα destroy and create a quasiparticle with momentum p in one of the three polarizations α = x, y, z. Interaction between one-and two-particle states is, generally, described by two types of cubic vertices shown in Fig. 2a,b. In superfluid 4 He presence of such particle non-conserving processes is determined by a Bose condensate, which absorbs or emits an extra particle. 8,12 In quantum spin systems with singlet ground states one finds a more diverse situation. Symmetry of a majority of low-dimensional dimer systems, like, fo...

show abstract

mentioning

confidence: 99%

“…The lowenergy triplet of magnons can be split due to intrinsic anisotropies or under applied magnetic field. Recent neutron experiments 5,6 on two organic spin-gap materials PHCC and IPA-CuCl 3 have revealed drastic transformation of triplet quasiparticles undergoing at high energies. Upon entering two-magnon continuum, see Fig.…”

mentioning

confidence: 99%

Decay of quasiparticles in quantum spin liquids

Zhitomirsky

2006

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…In particular, it is uncertain at this point whether the decay process considered above fully describes its dynamics. In addition to the multimagnon continuum [27][28][29][30] , other channels such as decays into vortex-like excitations are conceivable in two-dimensional planar magnets and require further investigation. It would be also interesting to compare the results presented herein with the spectra from resonant inelastic X-ray scattering, which can in principle access both the scalar and longitudinal susceptibilities.…”

mentioning

confidence: 99%

Higgs mode and its decay in a two-dimensional antiferromagnet

et al. 2017

View full text Add to dashboard Cite

Condensed-matter analogues of the Higgs boson in particle physics allow insights into its behaviour in di erent symmetries and dimensionalities 1 . Evidence for the Higgs mode has been reported in a number of di erent settings, including ultracold atomic gases 2 , disordered superconductors 3 , and dimerized quantum magnets 4 . However, decay processes of the Higgs mode (which are eminently important in particle physics)have not yet been studied in condensed matter due to the lack of a suitable material system coupled to a direct experimental probe. A quantitative understanding of these processes is particularly important for low-dimensional systems, where the Higgs mode decays rapidly and has remained elusive to most experimental probes. Here, we discover and study the Higgs mode in a two-dimensional antiferromagnet using spin-polarized inelastic neutron scattering. Our spin-wave spectra of Ca 2 RuO 4 directly reveal a well-defined, dispersive Higgs mode, which quickly decays into transverse Goldstone modes at the antiferromagnetic ordering wavevector. Through a complete mapping of the transverse modes in the reciprocal space, we uniquely specify the minimal model Hamiltonian and describe the decay process. We thus establish a novel condensed-matter platform for research on the dynamics of the Higgs mode.For a system of interacting spins, amplitude fluctuations of the local magnetization-the Higgs mode-can exist as well-defined collective excitations near a quantum critical point (QCP). We consider here a magnetic instability driven by the intra-ionic spinorbit coupling, which tends towards a non-magnetic state through complete cancellation of orbital (L) and spin (S) moments when they are antiparallel and of equal magnitude 5,6 . This mechanism should be broadly relevant for d 4 compounds of such ions as Ir(V), Ru(IV), Os(IV) and Re(III) with sizable spin-orbit coupling but remains little explored. We investigate the magnetic insulator Ca 2 RuO 4 , a quasi-two-dimensional antiferromagnet 7 with nominally L = 1 and S = 1 (Fig. 1). Because the local symmetry around the Ru(IV) ion is very low 8,9 (having only inversion symmetry), it is widely believed that the orbital moment is completely quenched by the crystalline electric field 10-13 , which is dominated by the compressive distortion of the RuO 6 octahedra along the c-axis (Fig. 1). In the absence of an orbital moment, the nearest-neighbour magnetic exchange interaction is necessarily isotropic. Deviations from this behaviour are a sensitive indicator of an unquenched orbital moment. If this moment is sufficiently strong, it can drive Ca 2 RuO 4 close to a QCP with novel Higgs physics.Our comprehensive set of time-of-flight (TOF) inelastic neutron scattering (INS) data over the full Brillouin zone (Fig. 2a) indeed reveal qualitative deviations of the transverse spin-wave dispersion from those of a Heisenberg antiferromagnet. In particular, the global maximum of the dispersion is found at q = (0,0), in sharp contrast to a Heisenberg antiferromagnet, which has a...

show abstract

“…This confirms a peculiar symmetry of the ladder spin Hamiltonian which is invariant under leg permutation [44]. In a previously studied asymmetric ladder the magnons become unstable at certain wave vectors [13]. T. Yankova et al The most recent experiments were carried out at the Cold Neutron Chopper Spectrometer CNCS [46] at Oak Ridge National Laboratory and revealed stunning new details [45].…”

Section: Preparing the Crystals For Experimentsmentioning

confidence: 68%

“…Recent breakthroughs were therefore achieved in studies of organic quantum magnets, particularly in transition metal complexes. Among these compounds, for neutron experiments, one finds excellent one-dimensional [10][11][12][13][14] and two-dimensional [15][16][17] spin networks with varying degrees of geometric frustration [15,18] and typical magnetic energy scales of 1 meV. These energies correspond to temperatures [19][20][21][22] and magnetic fields [23][24][25][26][27] that can be realized in neutron experiments.…”

Section: Challenges In Quantum Magnetismmentioning

confidence: 99%

Crystals for neutron scattering studies of quantum magnetism

Yankova

Hüvonen

Mühlbauer

et al. 2012

Philosophical Magazine

Self Cite

View full text Add to dashboard Cite

We review a strategy for targeted synthesis of large single crystal samples of prototype quantum magnets for inelastic neutron scattering experiments. Four case studies of organic copper halogenide S = 1/2 systems are presented. They are meant to illustrate that exciting experimental results pertaining to forefront many-body quantum physics can be obtained on samples grown using very simple techniques, standard laboratory equipment, and almost no experience in in advanced crystal growth techniques.

show abstract

Dynamics of Composite Haldane Spin Chains inIPA−CuCl3

Cited by 134 publications

References 21 publications

Decay of quasiparticles in quantum spin liquids

Decay of quasiparticles in quantum spin liquids

Higgs mode and its decay in a two-dimensional antiferromagnet

Crystals for neutron scattering studies of quantum magnetism

Contact Info

Product

Resources

About