Detection of orbital fluctuations above the structural transition temperature in the iron pnictides and chalcogenides

2012/01/31 by H. Z. Arham, Hamood Z. Arham, C. R. Hunt +26 · 54 citations
Biochemistry, Genetics and Molecular Biology · Materials Science · Physics and Astronomy · #Amyloidosis: Diagnosis, Treatment, Outcomes #Anisotropy #Condensed matter physics #Doping #Electrical engineering #Electrical resistivity and conductivity #Geometry #Iron-based superconductors research #Optics #Physics #Plane (geometry) #Quantum mechanics #Resistive touchscreen #Spectroscopy #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.85.214515

published in Physical Review B 85(21) (American Physical Society) · Accepted for publication in Physical Review B

arxiv created 2012/06/04 · openalex publication_date 2012/06/18 · arxiv updated 2016/11/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We use point-contact spectroscopy (PCS) to probe AEFe₂As₂ (AE=Ca,\phantom\rule4.pt0exSr,\phantom\rule4.pt0exBa) and Fe_1+yTe. For AE=Sr,Ba we detect orbital fluctuations above T_S while for AE=Ca these fluctuations start below T_S. Co doping preserves the orbital fluctuations while K doping suppresses it. The fluctuations are only seen at those dopings and temperatures where an in-plane resistive anisotropy is known to exist. We predict an in-plane resistive anisotropy of Fe_1+yTe above T_S. Our data are examined in light of the recent work by Lee and Phillips (arXiv:1110.5917v2). We also study how joule heating in the PCS junctions impacts the spectra. Spectroscopic information is only obtained from those PCS junctions that are free of heating effects while those PCS junctions that are in the thermal regime display bulk resistivity phenomena.

Citations

• Non-Fermi Liquid due to Orbital Fluctuations in Iron Pnictide Superconductors
• Theory of electron nematic order in LaFeAsO
• The puzzle of high temperature superconductivity in layered iron pnictides and chalcogenides
• Symmetry-breaking orbital anisotropy observed for detwinned Ba(Fe 1- x Co x ) 2 As 2 above the spin density wave transition
• Orbital ordering and unfrustrated(π,0)magnetism from degenerate double exchange in the iron pnictides
• First-order structural phase transition inCaFe2As2
• Andreev Reflection in Heavy-Fermion Superconductors and Order Parameter Symmetry inCeCoIn5
• Finite-temperature spin dynamics and phase transitions in spin-orbital models
• Andreev reflection and order parameter symmetry in heavy-fermion superconductors: the case of CeCoIn5

Cited by

• Point Contact Spectroscopy of Fe Pnictides & Chalcogenides In The Normal State
• Recent Progress of Point Contact Spectroscopy as a Probe of Correlated Electron States
• Doping and critical-temperature dependence of the energy gaps in Ba(Fe1−xCox)2As2thin films
• Quantum criticality in the 122 iron pnictide superconductors emerging from orbital-selective Mottness

Related

• Strong electron-lattice coupling and orbital fluctuations in iron pnictide superconductor Ba(Fe1-xCox)2As2
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A_xFe_2-ySe₂ (A=K, Rb) Superconductors
• On the origin of the electronic anisotropy in iron pnicitde superconductors
• Weak Superconducting Fluctuations and Small Anisotropy of the Upper Critical Fields in an Fe1.05Te0.85Se0.15 Single Crystal
• Electronic properties of single-crystalline Fe_1.05Te and Fe_1.03Se_0.30Te_0.70