Field-induced Bose-Einstein condensation and supersolid in the two-dimensional Kondo necklace

Wei-Lin Tu^1*, Eun-Gook Moon², Kwan-Woo Lee^1,3, Warren E. Pickett⁴, Hyun-Yong Lee^1,3,5

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, email:weilintu@korea.ac.kr

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