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Title: Quantum phase transition inside the superconducting dome of Ba(Fe 1− x Co x ) 2 As 2 from diamond-based optical magnetometry

Abstract

Unconventional superconductivity often emerges in close proximity to a magnetic instability. Upon suppressing the magnetic transition down to zero temperature by tuning the carrier concentration, pressure, or disorder, the superconducting transition temperature $$T_c$$ acquires its maximum value. A major challenge is the elucidation of the relationship between the superconducting phase and the strong quantum fluctuations expected near a quantum phase transition (QPT) that is either second order (i.e. a quantum critical point) or weakly first order. While unusual normal state properties, such as non-Fermi liquid behavior of the resistivity, are commonly associated with strong quantum fluctuations, evidence for its presence inside the superconducting dome are much scarcer. In this paper, we use sensitive and minimally invasive optical magnetometry based on NV-centers in diamond to probe the doping evolution of the $T=0$ penetration depth in the electron-doped iron-based superconductor Ba(Fe$$_{1-x}$$Co$$_x$$)$$_2$$As$$_2$$. A non-monotonic evolution with a pronounced peak in the vicinity of the putative magnetic QPT is found. This behavior is reminiscent to that previously seen in isovalently-substituted BaFe$$_2$$(As$$_{1-x}$$P$$_x$$)$$_2$$ compounds, despite the notable differences between these two systems. Whereas the latter is a very clean system that displays nodal superconductivity and a single simultaneous first-order nematic-magnetic transition, the former is a charge-doped and significantly dirtier system with fully gapped superconductivity and split second-order nematic and magnetic transitions. Thus, our observation of a sharp peak in $$\lambda (x) $$ near optimal doping, combined with the theoretical result that a QPT alone does not mandate the appearance of such peak, unveils a puzzling and seemingly universal manifestation of magnetic quantum fluctuations in iron-based superconductors and unusually robust quantum phase transition under the dome of superconductivity.

Authors:
ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
Ames Lab., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
OSTI Identifier:
1631336
Alternate Identifier(s):
OSTI ID: 1609155
Report Number(s):
IS-J-10,185
Journal ID: ISSN 1367-2630
Grant/Contract Number:  
AC02-07CH11358; SC0012336; SC0017888; SC0020313
Resource Type:
Published Article
Journal Name:
New Journal of Physics
Additional Journal Information:
Journal Name: New Journal of Physics Journal Volume: 22 Journal Issue: 5; Journal ID: ISSN 1367-2630
Publisher:
IOP Publishing
Country of Publication:
United Kingdom
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Joshi, K. R., Nusran, N. M., Tanatar, M. A., Cho, K., Bud’ko, S. L., Canfield, P. C., Fernandes, R. M., Levchenko, A., and Prozorov, R. Quantum phase transition inside the superconducting dome of Ba(Fe 1− x Co x ) 2 As 2 from diamond-based optical magnetometry. United Kingdom: N. p., 2020. Web. https://doi.org/10.1088/1367-2630/ab85a9.
Joshi, K. R., Nusran, N. M., Tanatar, M. A., Cho, K., Bud’ko, S. L., Canfield, P. C., Fernandes, R. M., Levchenko, A., & Prozorov, R. Quantum phase transition inside the superconducting dome of Ba(Fe 1− x Co x ) 2 As 2 from diamond-based optical magnetometry. United Kingdom. https://doi.org/10.1088/1367-2630/ab85a9
Joshi, K. R., Nusran, N. M., Tanatar, M. A., Cho, K., Bud’ko, S. L., Canfield, P. C., Fernandes, R. M., Levchenko, A., and Prozorov, R. Fri . "Quantum phase transition inside the superconducting dome of Ba(Fe 1− x Co x ) 2 As 2 from diamond-based optical magnetometry". United Kingdom. https://doi.org/10.1088/1367-2630/ab85a9.
@article{osti_1631336,
title = {Quantum phase transition inside the superconducting dome of Ba(Fe 1− x Co x ) 2 As 2 from diamond-based optical magnetometry},
author = {Joshi, K. R. and Nusran, N. M. and Tanatar, M. A. and Cho, K. and Bud’ko, S. L. and Canfield, P. C. and Fernandes, R. M. and Levchenko, A. and Prozorov, R.},
abstractNote = {Unconventional superconductivity often emerges in close proximity to a magnetic instability. Upon suppressing the magnetic transition down to zero temperature by tuning the carrier concentration, pressure, or disorder, the superconducting transition temperature $T_c$ acquires its maximum value. A major challenge is the elucidation of the relationship between the superconducting phase and the strong quantum fluctuations expected near a quantum phase transition (QPT) that is either second order (i.e. a quantum critical point) or weakly first order. While unusual normal state properties, such as non-Fermi liquid behavior of the resistivity, are commonly associated with strong quantum fluctuations, evidence for its presence inside the superconducting dome are much scarcer. In this paper, we use sensitive and minimally invasive optical magnetometry based on NV-centers in diamond to probe the doping evolution of the $T=0$ penetration depth in the electron-doped iron-based superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. A non-monotonic evolution with a pronounced peak in the vicinity of the putative magnetic QPT is found. This behavior is reminiscent to that previously seen in isovalently-substituted BaFe$_2$(As$_{1-x}$P$_x$)$_2$ compounds, despite the notable differences between these two systems. Whereas the latter is a very clean system that displays nodal superconductivity and a single simultaneous first-order nematic-magnetic transition, the former is a charge-doped and significantly dirtier system with fully gapped superconductivity and split second-order nematic and magnetic transitions. Thus, our observation of a sharp peak in $\lambda (x) $ near optimal doping, combined with the theoretical result that a QPT alone does not mandate the appearance of such peak, unveils a puzzling and seemingly universal manifestation of magnetic quantum fluctuations in iron-based superconductors and unusually robust quantum phase transition under the dome of superconductivity.},
doi = {10.1088/1367-2630/ab85a9},
journal = {New Journal of Physics},
number = 5,
volume = 22,
place = {United Kingdom},
year = {2020},
month = {5}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1088/1367-2630/ab85a9

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Works referenced in this record:

Quantum criticality in organic conductors? Fermi liquid versus non-Fermi-liquid behaviour
journal, July 2011


Phase transition beneath the superconducting dome in BaFe 2 ( As 1 x P x ) 2
journal, August 2015


Pairing Mechanism in Fe-Based Superconductors
journal, March 2012


Measuring magnetic field texture in correlated electron systems under extreme conditions
journal, December 2019


A peak in the critical current for quantum critical superconductors
journal, January 2018


A Quantum Critical Point Lying Beneath the Superconducting Dome in Iron Pnictides
journal, March 2014


Quantum criticality in the iron pnictides and chalcogenides
journal, May 2011


Antiferromagnetic criticality at a heavy-fermion quantum phase transition
journal, September 2009

  • Knafo, W.; Raymond, S.; Lejay, P.
  • Nature Physics, Vol. 5, Issue 10
  • DOI: 10.1038/nphys1374

Where is the quantum critical point in the cuprate superconductors?
journal, March 2010


The break-up of heavy electrons at a quantum critical point
journal, July 2003

  • Custers, J.; Gegenwart, P.; Wilhelm, H.
  • Nature, Vol. 424, Issue 6948
  • DOI: 10.1038/nature01774

What lies beneath the dome?
journal, March 2008


Unconventional Quantum Criticality in Heavy-Fermion Compounds
journal, March 2011


Divergent Nematic Susceptibility in an Iron Arsenide Superconductor
journal, August 2012


Magnetically mediated superconductivity in heavy fermion compounds
journal, July 1998

  • Mathur, N. D.; Grosche, F. M.; Julian, S. R.
  • Nature, Vol. 394, Issue 6688
  • DOI: 10.1038/27838

Quantum criticality in heavy-fermion metals
journal, March 2008

  • Gegenwart, Philipp; Si, Qimiao; Steglich, Frank
  • Nature Physics, Vol. 4, Issue 3
  • DOI: 10.1038/nphys892

High-temperature superconductivity in iron-based materials
journal, August 2010

  • Paglione, Johnpierre; Greene, Richard L.
  • Nature Physics, Vol. 6, Issue 9
  • DOI: 10.1038/nphys1759

NMR Evidence for Inhomogeneous Nematic Fluctuations in BaFe 2 ( As 1 x P x ) 2
journal, March 2016


A common thread: The pairing interaction for unconventional superconductors
journal, October 2012


Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
journal, May 2016


Quantum criticality in electron-doped BaFe2−xNixAs2
journal, August 2013

  • Zhou, R.; Li, Z.; Yang, J.
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms3265

A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
journal, June 2012


Superconductivity gets an iron boost
journal, March 2010


Geometric edge barrier in the Shubnikov phase of type-II superconductors
journal, September 2001


Isotropic quantum scattering and unconventional superconductivity
journal, November 2008


Lattice symmetry breaking in cuprate superconductors: stripes, nematics, and superconductivity
journal, November 2009


Effective Demagnetizing Factors of Diamagnetic Samples of Various Shapes
journal, July 2018


FeAs-Based Superconductivity: A Case Study of the Effects of Transition Metal Doping on BaFe 2 As 2
journal, August 2010


Progress and perspectives on electron-doped cuprates
journal, September 2010


Transport near a quantum critical point in BaFe2(As1−xPx)2
journal, January 2014

  • Analytis, James G.; Kuo, H-H.; McDonald, Ross D.
  • Nature Physics, Vol. 10, Issue 3
  • DOI: 10.1038/nphys2869

Spatially-resolved study of the Meissner effect in superconductors using NV-centers-in-diamond optical magnetometry
journal, April 2018


Scattering and Pairing in Cuprate Superconductors
journal, August 2010


Anomalous critical fields in quantum critical superconductors
journal, December 2014

  • Putzke, C.; Walmsley, P.; Fletcher, J. D.
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms6679

Quantum critical behavior in heavy electron materials
journal, May 2014

  • Yang, Y. -f.; Pines, D.
  • Proceedings of the National Academy of Sciences, Vol. 111, Issue 23
  • DOI: 10.1073/pnas.1407561111