Field-induced double dome and Bose-Einstein condensation in the crossing quantum spin chain system AgVOAsO4

Abstract

We present inelastic neutron scattering data on the quantum paramagnet AgVOAsO 4 that establish the system is a S = 1/2 alternating spin chain compound and provide a direct measurement of the spin gap. We also present experimental evidence for two different types of field-induced magnetic order between µ 0 H c1 = 8.4 T and µ 0 H c2 = 48.9 T, which may be related to Bose-Einstein condensation (BEC) of triplons. Thermodynamic measurements in magnetic fields up to 60 T and temperatures down to 0.1 K reveal a H − T phase diagram consisting of a dome encapsulating two ordered phases with maximum ordering temperatures of 3.8 K and 5.3 K respectively. This complex phase diagram is not expected for a single-Q BEC system and therefore establishes AgVOAsO 4 as a promising multi-Q BEC candidate capable of hosting exotic vortex phases. 1 arXiv:1902.04633v1 [cond-mat.str-el]

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

“…We compare NaVOPO 4 with the isostructural compounds NaVOAsO 4 arXiv:1909.00117v1 [cond-mat.str-el] 31 Aug 2019 and AgVOAsO 4 to understand the underlying structureproperty relationship. [22][23][24][25] The aforementioned V 4+ phosphates and arsenates crystallize in the monoclinic crystal structure (space group P 2 1 /c). One peculiarity of this series is that the structural chains formed by the corner-sharing VO 6 octahedra do not represent the magnetic chains [24,25].…”

“…[22][23][24][25] The aforementioned V 4+ phosphates and arsenates crystallize in the monoclinic crystal structure (space group P 2 1 /c). One peculiarity of this series is that the structural chains formed by the corner-sharing VO 6 octahedra do not represent the magnetic chains [24,25]. Band structure calculations reveal that the magnetic chains run along the extended V-O-As-O-V path, whereas the shorter V-O-V path along the structural chains gives rise to a weak and ferromagnetic (FM) interaction J c −5 K. There exists another weak AFM interaction J a 8 K, which along with J c constitutes a frustrated 3D interaction network between the chains [same as Fig.…”

Quasi-one-dimensional magnetism in the spin- 12 antiferromagnet BaNa2Cu(VO4)2Sebastian1, Somesh2, Nandi3 et al. 2021Phys. Rev. B21080View full textAdd to dashboardCite

“…Such displacements do not occur in BaNa 2 Cu(VO 4 ) 2 , but they may potentially appear in sister compounds, because even the substitution of Na + by Ag + causes significant structural changes, although the two ions are very similar in size. Alternatively, one may consider structure types with a weaker spatial separation between the crossed chains that, in turn, allows several nonequivalent interactions to form a frustrated topology even in the absence of lateral displacements [64][65][66].…”

The Fascinating World of Low-Dimensional Quantum Spin Systems: Ab Initio Modeling

“…It is worth mentioning at this point that other attempts at ab initio modeling of low-dimensional quantum spin systems also exist, which use a variety of methods, such as the extended Huckel tight-binding method (EHTB) [ 21 ], tight-binding fitting of the density function theory (DFT) band structure in terms of Slater–Koster parametrization, and total energy calculations. For representative references, see [ 22 , 23 , 24 , 25 , 26 ]. In addition to quantum Monte Carlo (QMC) and exact diagonalization, methods like the density matrix renormalization group (DMRG) [ 27 ], bond-operator theory, variational Ansätze, etc.…”