Field-induced Bose-Einstein condensation and supersolid in the two-dimensional Kondo necklace
Wei-Lin Tu1*, Eun-Gook Moon2, Kwan-Woo Lee1,3, Warren E. Pickett4, Hyun-Yong Lee1,3,5
1Division of Display and Semiconductor Physics, Korea University, Sejong, Korea
2Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
3Department of Applied Physics, Korea University, Sejong, Korea
4Department of Physics, University of California, Davis, California, USA
5Interdisciplinary Program in E·ICT-Culture-Sports Convergence, Korea University, Sejong, Korea
* Presenter:Wei-Lin Tu,
We report our numerical calculation using two-dimensional tensor network ansatz, infinite projected entangled-pair state (iPEPS), on the 2D Kondo-necklace model where a local spin-singlet phase can be realized. By introducing an external magnetic field, the singlet-triplet gap reduces and eventually closes, leading to the well-known triplon condensation. Moreover, after introducing XXZ anisotropy, this model gives rise to a field-induced supersolid before entering a fully polarized phase. In 3D, the Kondo-sieve model is regarded as the spin Hamiltonian for Ba₂NiO₂(AgSe)₂ (BNOAS), and thus we believe our numerical estimation can be realized and provide a new platform for such exotic field-induced condensation. Finally, we propose a t-J-K many-body Hamiltonian that is appropriate for exploring the expected superconductivity upon doping electrons into BNOAS.

Keywords: Spin superfluid, Spin supersolid, Tensor network, Infinite projected entangled-pair state, High-Tc superconductivity