Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTe2O6

Abstract

The magnetic Hamiltonian of the Heisenberg quantum antiferromagnet SrCuTe 2 O 6 is studied by inelastic neutron scattering technique on powder and single-crystalline samples above and below the magnetic transition temperatures at 8 and 2 K. The high-temperature spectra reveal a characteristic diffuse scattering corresponding to a multispinon continuum, confirming the dominant quantum spin chain behavior due to the third neighbor interaction J intra = 4.22 meV (49 K). The low-temperature spectra exhibit sharper excitations at energies <1.25 meV, which can be explained by considering a combination of weak antiferromagnetic first nearest neighbor interchain coupling J 1 = 0.17 meV (1.9 K) and even weaker ferromagnetic second nearest neighbor J 2 = −0.037 meV (−0.4 K) or a weak ferromagnetic J 2 = −0.11 meV (−1.3 K) and antiferromagnetic J 6 = 0.16 meV (1.85 K), giving rise to the long-range magnetic order and spin-wave excitations at low energies. These results suggest that SrCuTe 2 O 6 is a highly one-dimensional Heisenberg system with three mutually perpendicular spin chains coupled by a weak ferromagnetic J 2 in addition to the antiferromagnetic J 1 or J 6 , presenting a contrasting scenario from the highly frustrated hyper-hyperkagome lattice (equally strong antiferromagnetic J 1 and J 2 ) found in the isostructural quantum spin liquid candidate PbCuTe 2 O 6 .

A plausible investigation of low dimensional magnetism in a 3D spin system PrVO4

“…4(b) depicts the T -dependent C m at zero field, which is manifested by the presence of a broad maximum centered at about 14 K. This broad maximum is believed to arise due to the presence of short-range spin correlations, indicating toward the low D magnetism and has been reported in various S = ½ as well as S = 1 chain compounds. 15–18,39,40,42 Generally, this kind of broad maximum in C m is a signature of short-range magnetic interactions among the spins and is found to exist at a relatively lower temperature than the broad maximum observed in magnetic susceptibility. Another notable feature is that the C m remains almost zero up to a finite temperature (∼4 K) before showing a rapid increase at higher temperatures.…”

“…Recently, the series ACuTe 2 O 6 (A = Pb, Ba, Sr) has gained a lot of interest in the context of QSL state and low D magnetism. 7,8,15–18 The magnetic properties in this series do not only depend on the 1 st near neighbor (NN) but also on the next NN interactions. In particular, the Pb-based member exhibits field induced QSL state due to the dominance of a highly-frustrated Hyperkagome network formed by the 1 st and 2 nd NN magnetic interactions.…”

Crystal growth, characterization and phase transition of PbCuTe$_2$O$_6$

“…In case the frustration is lowered allowing magnetic order to occur, the expected ordered moment will be very small as the spectral weight of the excitations is lowered below ∼0.4 meV at lower temperature [8]. When compared to the simulated diffraction magnetic Bragg peak and the energy scale of the spin waves in the isostructural unfrustrated compound SrCuTe 2 O 6 which develops long-range magnetic order (1.25 meV ) [33,34], the ordered moment in PCTO can be estimated to be less than 0.1µ B . It should however be noted that the magnetic measurement of C.Thurn et.al [15] do not find an accompanying magnetic transition, rather suggesting that the highly frustrated state survives in the single crystal below the transition with enhanced quantum critical behavior compared to the powders.…”

Magnetic excitation spectrum and Hamiltonian of the quantum spin chain compound BaCuTe2O6

“…The interchain interactions were also investigated by inelastic neutron scattering. By fitting the lowenergy magnetic spectrum at low temperatures to spin-wave theory, Chillal et al [17] showed that the FM J 2 /AFM J 6 model is compatible with the data while an AFM J 1 also explains the spectrum.…”

“…Evidence for this comes from broad peaks due to short-range order in the DC susceptibility and heat capacity [12][13][14][15][16]. Furthermore, inelastic neutron scattering finds that the excitations form a spinon continuum characteristic of the spin-1/2 Heisenberg antiferromagnetic chain [17]. Physical properties measurements also reveal two transitions to long-range magnetic order and a complex phase diagram as a function of magnetic field and temperature [12][13][14][15][16].…”