Surface Nematic Order in Iron Pnictides

Abstract

Electronic nematicity plays important role in iron-based superconductors. These materials have layered structure and theoretical description of their magnetic and nematic transitions has been well established in two-dimensional approximation, i.e., when the layers can be treated independently. However, the interaction between iron layers mediated by electron tunneling may cause non-trivial three-dimensional behavior. Starting from the simplest model for orbital nematic in a single layer, we investigate the influence of interlayer tunneling on bulk nematic order and possible preemptive state where this order is only formed near the surface. We found that the interlayer tunneling suppresses the bulk nematicity which makes favorable formation of a surface nematic above the bulk transition temperature. The purely electronic tunneling Hamiltonian, however, favors alternating from layer-to-layer nematic order parameter in the bulk. The uniform bulk state typically observed experimentally may be stabilized by the coupling with the elastic lattice deformation. Depending on strength of this coupling, we found three regimes: (i) surface nematic and alternating bulk order, (ii) surface nematic and uniform bulk order, and (iii) uniform bulk order without the intermediate surface phase. The intermediate surface-nematic state may resolve the current controversy about the existence of the weak "meta-nematic transition" in the compound BaFe${}_2$As${}_{2-x}$P${}_x$.

20 pages, 9 figures.; more references added, and minor revision

References in corpus (25)

• High-temperature superconductivity in iron-based materials
• Nematic order in iron superconductors - who is in the driver's seat?
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Theory of Electron Nematic Order in LaOFeAs
• Ising and Spin orders in Iron-based Superconductors
• Nematic and meta-nematic transitions in the iron pnictides
• The electronic phase diagram of the LaO1-xFxFeAs superconductor
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Phase Diagram of Ba1-xKxFe2As2
• Instability toward Formation of Quasi-One-Dimensional Fermi Surface in Two-Dimensional t-J Model
• Possible Quasi-One-Dimensional Fermi Surface in La_{2-x}Sr_{x}CuO_4
• Doping evoluton of antiferromagnetic order and structural distortion in LaFeAsO${}_{1-x}$F${}_x$
• Formation of Electronic Nematic Phase in Interacting Systems
• Effect of Co doping on the in-plane anisotropy in the optical spectrum of underdoped Ba(Fe1-xCox)2As2
• Emergence of Orbital Nematicity in the Tetragonal Phase of BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Spin-orbital interplay and topology in the nematic phase of iron pnictides
• Vertical loop nodes in iron-based superconductors
• Self-masking of spontaneous symmetry breaking in layer materials
• Study of antiferromagnetic and nematic phase transitions in $BaF{e}_2(A{s}_{1-x}{P}_x{)}_2$ by AC micro-calorimetry and SQUID magnetometry
• Itinerant scenario for Fe-pnictides: comparison with quantum Monte Carlo

Cited by in corpus (3)

• Imaging anomalous nematic order and strain in optimally doped BaFe${}_2$(As,P)${}_2$
• Imaging Nematic Transitions in Iron-Pnictide Superconductors with a Quantum Gas
• Defect-induced electronic smectic state at the surface of nematic materials