pith. sign in

arxiv: 2605.24536 · v1 · pith:Y6NFPOY7new · submitted 2026-05-23 · ❄️ cond-mat.supr-con · cond-mat.mtrl-sci· cond-mat.str-el

Nonunitary triplet superconductivity in the Z2 topological metal SrPd2As2

Aarti , Dibyendu Samanta , Kartik Panda , Devashibhai Adroja , Daloo Ram , Zakir Hossain , Rhea Stewart , Adrian Hillier
show 4 more authors
Amitava Bhattacharyya Samar Layek Sudeep Kumar Ghosh Vivek Kumar Anand
This is my paper

Pith reviewed 2026-06-30 12:12 UTC · model grok-4.3

classification ❄️ cond-mat.supr-con cond-mat.mtrl-scicond-mat.str-el
keywords nonunitary triplet superconductivitytime-reversal symmetry breakingZ2 topological metalfully gapped superconductormuon spin rotationSrPd2As2spin-orbit coupling
0
0 comments X

The pith

SrPd2As2 realizes a nonunitary triplet superconducting state that breaks time-reversal symmetry while remaining fully gapped.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines the superconducting ground state of the Z2 topological metal SrPd2As2. Transverse-field muon spin rotation shows a fully gapped state below Tc of 0.94 K, yet zero-field measurements detect spontaneous magnetic fields that signal broken time-reversal symmetry. First-principles calculations identify the material's topological character and open Fermi surface. Standard Migdal-Eliashberg theory predicts nodal gaps and an incorrect Tc, so the authors invoke the combined effects of spin-orbit coupling, tetragonal symmetry, and Fermi-surface topology to stabilize a nonunitary triplet state whose nodes fall away from occupied states.

Core claim

In SrPd2As2 the interplay of spin-orbit coupling, tetragonal symmetry, and an open Fermi surface topology stabilizes a nonunitary triplet superconducting state whose symmetry-imposed nodes lie in momentum-space regions devoid of electronic states. This yields a fully gapped thermodynamic response while naturally breaking time-reversal symmetry.

What carries the argument

The nonunitary triplet order parameter whose nodes are displaced from the occupied Fermi surface by the material's band topology and symmetry constraints.

If this is right

  • The superconducting state exhibits spontaneous internal magnetic fields below Tc due to time-reversal symmetry breaking.
  • Thermodynamic and transport probes register a fully gapped response despite the unconventional pairing symmetry.
  • Purely phonon-mediated pairing is ruled out because it predicts both nodal gaps and an overestimated Tc.
  • Surface states cross the Fermi level, consistent with the Z2 band topology.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same symmetry and Fermi-surface conditions could stabilize analogous nonunitary states in other tetragonal Z2 metals.
  • The bulk TRS-breaking yet fully gapped state may support protected surface modes detectable by tunneling spectroscopy.
  • High-resolution specific-heat or thermal-conductivity measurements under magnetic fields could further test the absence of low-energy excitations.

Load-bearing premise

The spontaneous internal magnetic fields detected by zero-field muSR below Tc originate from the bulk superconducting order parameter breaking time-reversal symmetry rather than from surface states, impurities, or other extrinsic sources.

What would settle it

Angle-resolved photoemission spectroscopy that finds gap nodes or gapless excitations on the Fermi surface below Tc would rule out the proposed fully gapped nonunitary state.

Figures

Figures reproduced from arXiv: 2605.24536 by Aarti, Adrian Hillier, Amitava Bhattacharyya, Daloo Ram, Devashibhai Adroja, Dibyendu Samanta, Kartik Panda, Rhea Stewart, Samar Layek, Sudeep Kumar Ghosh, Vivek Kumar Anand, Zakir Hossain.

Figure 1
Figure 1. Figure 1: (c) and in agreement with earlier electronic struc￾ture studies of SrPd2As2 [39, 40]. Introducing SOC leads to a clear splitting of the bands and opens a continu￾ous direct gap between the valence (purple) and conduc￾tion (green) sectors in the vicinity of EF , as shown in [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: (a)] which negates the extrinsic effects to be the origin of the increase in λZF below Tc, and confirms the appearance of static or quasistatic spontaneous magnetic field at T < Tc that leads to the TRS breaking in the SC state of SrPd2As2. From the λZF(T) in [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6 [PITH_FULL_IMAGE:figures/full_fig_p009_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7 [PITH_FULL_IMAGE:figures/full_fig_p010_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8 [PITH_FULL_IMAGE:figures/full_fig_p010_8.png] view at source ↗
Figure 10
Figure 10. Figure 10: FIG. 10 [PITH_FULL_IMAGE:figures/full_fig_p011_10.png] view at source ↗
Figure 9
Figure 9. Figure 9: FIG. 9 [PITH_FULL_IMAGE:figures/full_fig_p011_9.png] view at source ↗
read the original abstract

In Z2 topological metals, nontrivial band topology and strong spin-orbit coupling (SOC) impose symmetry constraints that can stabilize unconventional superconducting states, even when thermodynamic probes indicate an isotropic gap. Here, we investigate the superconducting ground state of such a material, SrPd2As2, using muon spin rotation and relaxation (muSR), first-principles calculations, and Ginzburg-Landau analysis. Transverse-field muSR indicates a fully gapped superconducting state below Tc = 0.94 K, while zero-field muSR detects spontaneous internal magnetic fields below Tc, establishing time-reversal symmetry (TRS) breaking. Electronic structure calculations identify SrPd2As2 as a Z2 topological metal with surface states crossing the Fermi level. Standard anisotropic Migdal-Eliashberg calculations predict a nodal gap and overestimate Tc, indicating that a purely phonon-mediated pairing mechanism is insufficient. We resolve this apparent contradiction by showing that the interplay of SOC, tetragonal symmetry, and an open Fermi surface topology stabilizes a nonunitary triplet superconducting state whose symmetry-imposed nodes lie in momentum-space regions devoid of electronic states. This yields a fully gapped thermodynamic response while naturally breaking TRS. Our results establish SrPd2As2 as a clean platform for bulk nonunitary triplet pairing and a promising candidate for intrinsic topological superconductivity.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 0 minor

Summary. The manuscript investigates the superconducting state of the Z2 topological metal SrPd2As2 using transverse- and zero-field muSR, first-principles electronic structure calculations, and Ginzburg-Landau symmetry analysis. It reports a fully gapped state below Tc = 0.94 K from TF-muSR, spontaneous internal fields below Tc from ZF-muSR indicating TRS breaking, identification as a Z2 metal with surface states crossing EF, and Migdal-Eliashberg calculations that predict nodal gaps and overestimate Tc. These observations are resolved by proposing a nonunitary triplet pairing state stabilized by SOC, tetragonal symmetry, and open Fermi-surface topology, with symmetry-imposed nodes lying in momentum regions devoid of states.

Significance. If the central interpretation holds, the work would establish SrPd2As2 as a platform for bulk nonunitary triplet superconductivity in a topological metal, demonstrating how SOC and band topology can stabilize unconventional pairing that appears fully gapped while breaking TRS. This has potential implications for intrinsic topological superconductivity and would highlight the limitations of purely phonon-mediated mechanisms in such systems.

major comments (3)
  1. [Abstract (zero-field muSR results)] Abstract, zero-field muSR paragraph: The detection of spontaneous internal magnetic fields below Tc is presented as establishing TRS breaking by the bulk superconducting order parameter, but the text provides no details on controls or analysis excluding extrinsic sources such as surface states crossing EF or dilute impurities; this interpretation is load-bearing for the motivation to invoke a nonunitary triplet state.
  2. [Ginzburg-Landau analysis] Ginzburg-Landau analysis: The nonunitary triplet state is introduced to simultaneously explain the fully gapped thermodynamics and TRS breaking; without explicit derivation showing that the symmetry constraints follow independently from tetragonal symmetry, SOC, and Fermi-surface topology (rather than being selected to fit the two observations), the central claim risks circularity.
  3. [Abstract (muSR and calculations)] Abstract (transverse-field muSR and Migdal-Eliashberg calculations): The claims of a fully gapped state and that phonon-mediated pairing is insufficient rest on muSR fits and calculations that overestimate Tc while predicting nodes, but no quantitative details on data analysis, error bars, fitting procedures, or specific Eliashberg parameters are provided, undermining assessment of these load-bearing results.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for their careful and constructive review of our manuscript. We address each of the major comments below, providing additional details and clarifications. Where the comments identify areas requiring more explicit information, we have revised the manuscript accordingly.

read point-by-point responses

  1. Referee: Abstract (zero-field muSR results)] Abstract, zero-field muSR paragraph: The detection of spontaneous internal magnetic fields below Tc is presented as establishing TRS breaking by the bulk superconducting order parameter, but the text provides no details on controls or analysis excluding extrinsic sources such as surface states crossing EF or dilute impurities; this interpretation is load-bearing for the motivation to invoke a nonunitary triplet state.

    Authors: We agree that the original manuscript lacked sufficient detail on the zero-field muSR controls. In the revised version, we have added an expanded methods section and a dedicated paragraph in the results describing the analysis: (i) temperature-dependent measurements above Tc showing no relaxation, (ii) checks for sample purity via magnetization and resistivity, (iii) comparison of the observed field distribution width to expectations for dilute impurities, and (iv) arguments that surface states crossing EF would produce a much smaller and temperature-independent contribution inconsistent with the data. These additions strengthen the case for bulk TRS breaking. revision: yes

  2. Referee: Ginzburg-Landau analysis: The nonunitary triplet state is introduced to simultaneously explain the fully gapped thermodynamics and TRS breaking; without explicit derivation showing that the symmetry constraints follow independently from tetragonal symmetry, SOC, and Fermi-surface topology (rather than being selected to fit the two observations), the central claim risks circularity.

    Authors: The symmetry analysis begins from the tetragonal point group D4h with SOC included, which restricts the allowed pairing channels to specific irreducible representations before any experimental input. We have now included an explicit, step-by-step derivation in the supplementary material showing the decomposition of the order parameter, the conditions for nonunitary states, and how the open Fermi-surface topology places the symmetry-required nodes in regions without spectral weight. This derivation is independent of the muSR observations and is presented prior to comparing with experiment, removing any appearance of circularity. revision: yes

  3. Referee: Abstract (muSR and calculations)] Abstract (transverse-field muSR and Migdal-Eliashberg calculations): The claims of a fully gapped state and that phonon-mediated pairing is insufficient rest on muSR fits and calculations that overestimate Tc while predicting nodes, but no quantitative details on data analysis, error bars, fitting procedures, or specific Eliashberg parameters are provided, undermining assessment of these load-bearing results.

    Authors: We acknowledge that the original submission omitted quantitative details on the data analysis. The revised manuscript now provides: (i) the exact fitting functions and Bayesian/Maximum-likelihood procedures used for the TF-muSR spectra, (ii) error bars and covariance matrices for the extracted gap magnitude, superfluid density, and relaxation rates, (iii) the full set of Migdal-Eliashberg parameters (including λ, phonon spectrum moments, and Coulomb pseudopotential), and (iv) direct comparison of calculated versus measured Tc. These additions allow readers to assess the robustness of the fully gapped conclusion and the insufficiency of the phonon-only mechanism. revision: yes

Circularity Check

0 steps flagged

No significant circularity in derivation chain

full rationale

The paper's chain proceeds from muSR observations of a full gap and TRS breaking, through DFT band-structure results identifying Z2 topology, to a Ginzburg-Landau symmetry analysis that selects a nonunitary triplet state whose nodes fall outside the occupied Fermi surface. No quoted equations, fitted parameters renamed as predictions, or self-citation chains are present that reduce the central claim to its inputs by construction. The symmetry constraints are presented as arising from the material's point-group and Fermi-surface topology rather than being reverse-engineered from the two observations.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claim rests on the domain assumption that zero-field muSR spontaneous fields below Tc directly indicate bulk TRS breaking in the superconducting state, and on the modeling choice that standard Migdal-Eliashberg calculations are sufficient to rule out phonon-mediated pairing. No free parameters or invented entities are explicitly introduced in the abstract.

axioms (2)
  • domain assumption Zero-field muSR spontaneous internal fields below Tc originate from the bulk superconducting order parameter breaking time-reversal symmetry.
    Invoked in the abstract paragraph reporting zero-field muSR results to establish TRS breaking.
  • domain assumption Anisotropic Migdal-Eliashberg calculations accurately capture the gap structure and Tc for a phonon-mediated mechanism in this material.
    Used to conclude that purely phonon-mediated pairing is insufficient when the calculation predicts nodes and overestimates Tc.

pith-pipeline@v0.9.1-grok · 5826 in / 1561 out tokens · 28653 ms · 2026-06-30T12:12:07.091793+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

86 extracted references · 2 canonical work pages

  1. [1]

    N. P. Armitage, E. J. Mele, and A. Vishwanath, Weyl and Dirac semimetals in three-dimensional solids, Rev. Mod. Phys. 90, 015001 (2018)

    2018

  2. [2]

    B. Q. Lv, T. Qian, and H. Ding, Experimental perspec- tive on three-dimensional topological semimetals, Rev. Mod. Phys. 93, 025002 (2021)

    2021

  3. [3]

    S. K. Ghosh, M. Smidman, T. Shang, J. F. Annett, A. D. Hillier, J. Quintanilla, and H. Yuan, Recent progress on superconductors with time-reversal symmetry breaking, J. Phys.: Condens. Matter 33, 033001 (2021)

    2021

  4. [4]

    G. M. Luke, Y. Fudamoto, K. M. Kojima, M. I. Larkin, J. Merrin, B. Nachumi, Y. J. Uemura, Y. Maeno, Z. Q. Mao, Y. Mori, H. Nakamura, and M. Sigrist, Time-reversal symmetry-breaking superconductivity in Sr2RuO4, Nature 394, 558 (1998)

    1998

  5. [5]

    Maeno, S

    Y. Maeno, S. Yonezawa, and A. Ramires, Still mystery after all these years – unconventional superconductivity of Sr 2RuO4, J. Phys. Soc. Jpn. 93, 062001 (2024)

    2024

  6. [6]

    P. K. Biswas, S. K. Ghosh, J. Zhao, D. A. Mayoh, N. Zhi- gadlo, X. Xu, C. Baines, A. Hillier, G. Balakrishnan, and M. R. Lees, Chiral singlet superconductivity in the weakly correlated metal LaPt3P, Nat. Commun. 12, 2504 (2021)

    2021

  7. [7]

    P. K. Biswas, H. Luetkens, T. Neupert, T. Stürzer, C. Baines, G. Pascua, A. P. Schnyder, M. H. Fischer, J. Goryo, M. R. Lees, H. Maeter, F. Brückner, H.-H. Klauss, M. Nicklas, P. J. Baker, A. D. Hillier, M. Sigrist, A. Amato, and D. Johrendt, Evidence for supercon- ductivity with broken time-reversal symmetry in locally noncentrosymmetric SrPtAs, Phys. Re...

    2013

  8. [8]

    A. D. Hillier, J. Quintanilla, and R. Cywinski, Evi- dence for time-reversal symmetry breaking in the noncen- trosymmetric superconductor LaNiC 2, Phys. Rev. Lett. 102, 117007 (2009)

    2009

  9. [9]

    A. D. Hillier, J. Quintanilla, B. Mazidian, J. F. Annett, and R. Cywinski, Nonunitary triplet pairing in the cen- trosymmetric superconductor LaNiGa 2, Phys. Rev. Lett. 109, 097001 (2012)

    2012

  10. [10]

    S. K. Ghosh, G. Csire, P. Whittlesea, J. F. Annett, M. Gradhand, B. Újfalussy, and J. Quintanilla, Quan- titative theory of triplet pairing in the unconventional superconductor LaNiGa 2, Phys. Rev. B 101, 100506 (2020)

    2020

  11. [11]

    J. R. Badger, Y. Quan, M. C. Staab, S. Sumita, A. Rossi, K. P. Devlin, K. Neubauer, D. S. Shulman, J. C. Fet- 12 tinger, P. Klavins, M. K. Susan, D. Aoki, I. M. Vishik, W. E. Pickett, and V. Taufour, Dirac lines and loop at the fermi level in the time-reversal symmetry breaking superconductor LaNiGa 2, Commun. Phys 5, 22 (2022)

    2022

  12. [12]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, N. Kase, A. D. Hillier, A. M. Strydom, and J. Akimitsu, Unconventional su- perconductivity in the cage-type compound Sc5Rh6Sn18, Phys. Rev. B 98, 024511 (2018)

    2018

  13. [13]

    Bhattacharyya, D

    A. Bhattacharyya, D. Adroja, N. Kase, A. Hillier, J. Akimitsu, and A. Strydom, Unconventional supercon- ductivity in Y 5Rh6Sn18 probed by muon spin relaxation, Sci. Rep. 5, 12926 (2015)

    2015

  14. [14]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, J. Quintanilla, A. D. Hillier, N. Kase, A. M. Strydom, and J. Akimitsu, Bro- ken time-reversal symmetry probed by muon spin re- laxation in the caged type superconductor Lu5Rh6Sn18, Phys. Rev. B 91, 060503 (2015)

    2015

  15. [15]

    Singh, M

    D. Singh, M. S. Scheurer, A. D. Hillier, D. T. Adroja, and R. P. Singh, Time-reversal-symmetry breaking and unconventional pairing in the noncentrosymmetric super- conductor La7Rh3, Phys. Rev. B 102, 134511 (2020)

    2020

  16. [16]

    D. A. Mayoh, A. D. Hillier, G. Balakrishnan, and M. R. Lees, Evidence for the coexistence of time-reversal sym- metry breaking and bardeen-cooper-schrieffer-like su- perconductivity in La 7Pd3, Phys. Rev. B 103, 024507 (2021)

    2021

  17. [17]

    Barker, D

    J. Barker, D. Singh, A. Thamizhavel, A. D. Hillier, M. R. Lees, G. Balakrishnan, D. M. Paul, and R. P. Singh, Unconventional superconductivity in La 7Ir3 re- vealed by muon spin relaxation: introducing a new family of noncentrosymmetric superconductor that breaks time- reversal symmetry, Phys. Rev. Lett. 115, 267001 (2015)

    2015

  18. [18]

    Bhattacharyya, M

    A. Bhattacharyya, M. R. Lees, K. Panda, P. P. Fer- reira, T. T. Dorini, E. Gaudry, L. T. F. Eleno, V. K. Anand, J. Sannigrahi, P. K. Biswas, R. Tripathi, and D. T. Adroja, Nodeless time-reversal symmetry break- ing in the centrosymmetric superconductor Sc5Co4Si10 probed by muon-spin spectroscopy, Phys. Rev. Mater. 6, 064802 (2022)

    2022

  19. [19]

    Shang, S

    T. Shang, S. K. Ghosh, J. Z. Zhao, L.-J. Chang, C. Baines, M. K. Lee, D. J. Gawryluk, M. Shi, M. Medarde, J. Quintanilla, and T. Shiroka, Time- reversal symmetry breaking in the noncentrosymmetric Zr3Ir superconductor, Phys. Rev. B 102, 020503 (2020)

    2020

  20. [20]

    V. K. Anand, A. Bhattacharyya, D. T. Adroja, K. Panda, P. K. Biswas, A. D. Hillier, and B. Lake, Time-reversal symmetry breaking and s-wave superconductivity in CaPd2Ge2: A µSR study, Phys. Rev. B 108, 224519 (2023)

    2023

  21. [21]

    Panda, D

    Aarti, K. Panda, D. T. Adroja, A. Bhattacharyya, P. K. Biswas, A. D. Hillier, B. Lake, S. Layek, and V. K. Anand, Time-reversal symmetry breaking in the s-wave superconductor CaPd 2As2 probed by µSR, Phys. Rev. B 110, 144506 (2024)

    2024

  22. [22]

    P. K. Meena, D. Samanta, S. Jangid, R. K. Kushwaha, R. Stewart, A. D. Hillier, S. K. Ghosh, and R. P. Singh, Superconductivity in hourglass dirac chain metals (Ti, Hf)IrGe, Adv. Sci. , e12434 (2025)

    2025

  23. [23]

    P. K. Meena, D. Samanta, S. Srivastava, P. Manna, S. K. Ghosh, and R. P. Singh, Nonsymmorphic symmetry pro- tected hourglass dirac chain topology and conventional superconductivity in ZrIrGe, Phys. Rev. B 112, 144515 (2025)

    2025

  24. [24]

    C. S. Yadav, S. K. Ghosh, P. Kumar, A. Thamizhavel, and P. L. Paulose, Signature of point nodal superconduc- tivity in the dirac semimetal PdTe, Phys. Rev. B 110, 054515 (2024)

    2024

  25. [25]

    Shang, S

    T. Shang, S. K. Ghosh, M. Smidman, D. J. Gawryluk, C. Baines, A. Wang, W. Xie, Y. Chen, M. O. Ajeesh, M. Nicklas, E. Pomjakushina, M. Medarde, M. Shi, J. F. Annett, H. Yuan, J. Quintanilla, and T. Shiroka, Spin- triplet superconductivity in Weyl nodal-line semimetals, npj Quantum Mater. 7, 1 (2022)

    2022

  26. [26]

    K. P. Sajilesh, R. K. Kushwaha, D. Samanta, T. Tula, P. K. Meena, S. Srivastava, D. Singh, P. K. Biswas, A. Kanigel, A. D. Hillier, S. K. Ghosh, and R. P. Singh, Time-reversal symmetry breaking superconductivity in HfRhGe: A noncentrosymmetric weyl semimetal, Adv. Mater. 37, 2415721 (2025)

    2025

  27. [27]

    S. K. Ghosh, P. K. Biswas, C. Xu, B. Li, J. Z. Zhao, A. D. Hillier, and X. Xu, Time-reversal symmetry breaking su- perconductivity in three-dimensional Dirac semimetallic silicides, Phys. Rev. Res. 4, L012031 (2022)

    2022

  28. [28]

    Neupert, M

    T. Neupert, M. M. Denner, J.-X. Yin, R. Thomale, and M. Z. Hasan, Charge order and superconductivity in kagome materials, Nat. Phys. 18, 137 (2022)

    2022

  29. [29]

    V. K. Anand, H. Kim, A. Tanatar, Makariy, R. Prozorov, and C. Johnston, David, Superconductivity and physical properties of CaPd 2Ge2 single crystals, J. Phys.: Con- dens. Matter 26, 405702 (2014)

    2014

  30. [30]

    V. K. Anand, H. Kim, M. A. Tanatar, R. Prozorov, and D. C. Johnston, Superconducting and normal-state prop- erties of APd 2As2 (A= Ca, Sr, Ba) single crystals, Phys. Rev. B 87, 224510 (2013)

    2013

  31. [31]

    F. L. Pratt, WIMDA: A muon data analysis program for the windows PC, Physica B: Condens. Matter 289, 710 (2000)

    2000

  32. [32]

    Giannozzi, S

    P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococ- cioni, I. Dabo, A. D. Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Sc...

    2009

  33. [33]

    Giannozzi, O

    P. Giannozzi, O. Andreussi, T. Brumme, O. Bunau, M. B. Nardelli, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, M. Cococcioni, N. Colonna, I. Carnimeo, A. D. Corso, S. de Gironcoli, P. Delugas, R. A. DiStasio, A. Ferretti, A. Floris, G. Fratesi, G. Fugallo, R. Gebauer, U. Gerstmann, F. Giustino, T. Gorni, J. Jia, M. Kawa- mura, H.-Y. Ko, A. Kokalj, E. Kü...

    2017

  34. [34]

    Giannozzi, O

    P. Giannozzi, O. Baseggio, P. Bonfà, D. Brunato, R. Car, I. Carnimeo, C. Cavazzoni, S. de Gironcoli, P. Delugas, F. Ferrari Ruffino, A. Ferretti, N. Marzari, I. Timrov, A. Urru, and S. Baroni, Quantum ESPRESSO toward the exascale, The Journal of Chemical Physics 152, 154105 (2020). 13

    2020

  35. [35]

    J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 77, 3865 (1996)

    1996

  36. [36]

    Pizzi, V

    G. Pizzi, V. Vitale, R. Arita, S. Blügel, F. Freimuth, G. Géranton, M. Gibertini, D. Gresch, C. Johnson, T. Koretsune, J. Ibañez-Azpiroz, H. Lee, J.-M. Lihm, D. Marchand, A. Marrazzo, Y. Mokrousov, J. I. Mustafa, Y. Nohara, Y. Nomura, L. Paulatto, S. Poncé, T. Pon- weiser, J. Qiao, F. Thöle, S. S. Tsirkin, M. Wierzbowska, N. Marzari, D. Vanderbilt, I. Sou...

    2020

  37. [37]

    Q. Wu, S. Zhang, H.-F. Song, M. Troyer, and A. A. Soluyanov, Wanniertools: An open-source software pack- age for novel topological materials, Computer Physics Communications 224, 405 (2018)

    2018

  38. [38]

    V. K. Anand, P. K. Perera, A. Pandey, R. J. Goetsch, A. Kreyssig, and D. C. Johnston, Crystal growth and physical properties of SrCu 2As2, SrCu 2Sb2, and BaCu2Sb2, Phys. Rev. B 85, 214523 (2012)

    2012

  39. [39]

    Karaca, H

    E. Karaca, H. M. Tütüncü, H. Y. Uzunok, G. P. Srivas- tava, and Ş. Uǧur, Theoretical investigation of supercon- ductivity in SrPd2Ge2, SrPd2As2, and CaPd2As2, Phys. Rev. B 93, 054506 (2016)

    2016

  40. [40]

    Shein, S

    I. Shein, S. Skornyakov, V. Anisimov, and A. Ivanovskii, Elastic and electronic properties of superconduct- ing CaPd 2As2 and SrPd 2As2 vs. non-superconducting BaPd2As2, J. Superconduct. Nov. Magn. 27, 155 (2014)

    2014

  41. [41]

    L. M. Schoop, L. S. Xie, R. Chen, Q. D. Gibson, S. H. Lapidus, I. Kimchi, M. Hirschberger, N. Hal- dolaarachchige, M. N. Ali, C. A. Belvin, T. Liang, J. B. Neaton, N. P. Ong, A. Vishwanath, and R. J. Cava, Dirac metal to topological metal transition at a structural phase change in Au2Pb and prediction of Z2 topology for the superconductor, Phys. Rev. B 91...

    2015

  42. [42]

    Nayak, S.-C

    J. Nayak, S.-C. Wu, N. Kumar, C. Shekhar, S. Singh, J. Fink, E. E. Rienks, G. H. Fecher, S. S. Parkin, B. Yan, et al. , Multiple dirac cones at the surface of the topolog- ical metal LaBi, Nat. commun. 8, 13942 (2017)

    2017

  43. [43]

    B. R. Ortiz, S. M. L. Teicher, Y. Hu, J. L. Zuo, P. M. Sarte, E. C. Schueller, A. M. M. Abeykoon, M. J. Krogstad, S. Rosenkranz, R. Osborn, R. Seshadri, L. Ba- lents, J. He, and S. D. Wilson, CsV3Sb5: A Z2 topolog- ical kagome metal with a superconducting ground state, Phys. Rev. Lett. 125, 247002 (2020)

    2020

  44. [44]

    R. Yu, X. L. Qi, A. Bernevig, Z. Fang, and X. Dai, Equiv- alent expression of 𝟋2 topological invariant for band in- sulators using the non-abelian berry connection, Phys. Rev. B 84, 075119 (2011)

    2011

  45. [45]

    A. A. Soluyanov and D. Vanderbilt, Computing topolog- ical invariants without inversion symmetry, Phys. Rev. B 83, 235401 (2011)

    2011

  46. [46]

    A. D. Hillier, S. J. Blundell, I. McKenzie, I. Umegaki, L. Shu, J. A. Wright, T. Prokscha, F. Bert, K. Shimo- mura, A. Berlie, H. Alberto, and I. Watanabe, Muon spin spectroscopy, Nat. Rev. Methods Primers 2, 4 (2022)

    2022

  47. [47]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, M. Smidman, and V. K. Anand, A brief review on µSR studies of uncon- ventional Fe-and Cr-based superconductors, Sci. China Phys. Mech. Astron. 61, 127402 (2018)

    2018

  48. [48]

    McKenzie, The positive muon and µSR spectroscopy: powerful tools for investigating the structure and dynam- ics of free radicals and spin probes in complex systems, Annu

    I. McKenzie, The positive muon and µSR spectroscopy: powerful tools for investigating the structure and dynam- ics of free radicals and spin probes in complex systems, Annu. Rep. Sect. C Phys. Chem. 109, 65 (2013)

    2013

  49. [49]

    R. S. Hayano, Y. J. Uemura, J. Imazato, N. Nishida, T. Yamazaki, and R. Kubo, Zero-and low-field spin re- laxation studied by positive muons, Phys. Rev. B 20, 850 (1979)

    1979

  50. [50]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, J. S. Lord, L. Wang, Y. Shi, K. Panda, H. Luo, and A. M. Strydom, Quan- tum fluctuations in the quasi-one-dimensional non-fermi liquid system CeCo2Ga8 investigated using µSR, Phys. Rev. B 101, 214437 (2020)

    2020

  51. [51]

    T. Tula, G. Möller, J. Quintanilla, S. R. Giblin, A. D. Hillier, E. E. McCabe, S. Ramos, D. S. Barker, and S. Gibson, Machine learning approach to muon spec- troscopy analysis, Journal of Physics: Condensed Matter 33, 194002 (2021)

    2021

  52. [52]

    Panda, A

    K. Panda, A. Bhattacharyya, P. N. Ferreira, R. Mondal, A. Thamizhavel, D. T. Adroja, C. Heil, L. T. F. Eleno, and A. D. Hillier, Probing the superconducting gap struc- ture of ScRuSi via µSR and first-principles calculations, Phys. Rev. B 109, 224517 (2024)

    2024

  53. [53]

    D. T. Adroja, A. Bhattacharyya, Y. J. Sato, M. R. Lees, P. K. Biswas, K. Panda, V. K. Anand, G. B. G. Stenning, A. D. Hillier, and D. Aoki, Pairing symmetry of an inter- mediate valence superconductor CeIr 3 investigated using µSR measurements, Phys. Rev. B 103, 104514 (2021)

    2021

  54. [54]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, K. Panda, S. Saha, T. Das, A. J. S. Machado, O. V. Cigarroa, T. W. Grant, Z. Fisk, A. D. Hillier, and P. Manfrinetti, Evidence of a nodal line in the superconducting gap symmetry of non- centrosymmetric ThCoC 2, Phys. Rev. Lett. 122, 147001 (2019)

    2019

  55. [55]

    E. H. Brandt, Magnetic field density of perfect and im- perfect flux line lattices in type - II superconductors - I. application of periodic solutions, J. Low Temp. Phys. 73, 355 (1988)

    1988

  56. [56]

    E. H. Brandt, Properties of the ideal ginzburg-landau vortex lattice, Phys. Rev. B 68, 054506 (2003)

    2003

  57. [57]

    Panda, A

    K. Panda, A. Bhattacharyya, D. T. Adroja, N. Kase, P. K. Biswas, S. Saha, T. Das, R. Lees, Martin, and A. D. Hillier, Probing the superconducting ground state of ZrIrSi: A muon spin rotation and relaxation study, Phys. Rev. B 99, 174513 (2019)

    2019

  58. [58]

    Prozorov and R

    R. Prozorov and R. W. Giannetta, Magnetic penetra- tion depth in unconventional superconductors, Super- cond. Sci. Technol. 19, R41 (2006)

    2006

  59. [59]

    Bhattacharyya, P

    A. Bhattacharyya, P. P. Ferreira, K. Panda, S. H. Masunaga, L. R. de Faria, L. E. Correa, F. B. San- tos, D. T. Adroja, K. Yokoyama, T. T. Dorini, R. F. Jardim, L. T. F. Eleno, and A. J. S. Machado, Electron- phonon superconductivity in C-doped topological nodal- line semimetal Zr 5Pt3: A muon spin rotation and relax- ation (µSR) study, J. Phys.: Condens....

    2021

  60. [60]

    Bhattacharyya, D

    A. Bhattacharyya, D. T. Adroja, A. K. Jana, K. Panda, P. P. Ferreira, Y. Zhao, T. Ying, H. Hosono, T. T. Dorini, L. T. F. Eleno, P. K. Biswas, G. Stenning, R. Tripathi, and Y. Qi, Exploring superconductivity in Ba 3Ir4Ge16: Experimental and theoretical insights, J. Alloys Comp. 978, 173374 (2024)

    2024

  61. [61]

    J. F. Annett, Symmetry of the order parameter for high-temperature superconductivity, Adv. Phys. 39, 83 (1990)

    1990

  62. [62]

    G. M. Pang, M. Smidman, W. B. Jiang, J. K. Bao, Z. F. Weng, Y. F. Wang, L. Jiao, J. L. Zhang, G. H. Cao, 14 and H. Q. Yuan, Evidence for nodal superconductivity in quasi-one-dimensional K 2Cr3As3, Phys. Rev. B 91, 220502 (2015)

    2015

  63. [63]

    Carrington and F

    A. Carrington and F. Manzano, Magnetic penetration depth of MgB 2, Physica C 385, 205 (2003)

    2003

  64. [64]

    Bhattacharyya, K

    A. Bhattacharyya, K. Panda, D. T. Adroja, N. Kase, P. K. Biswas, S. Saha, T. Das, R. Lees, Martin, and A. D. Hillier, Investigation of superconducting gap struc- ture in HfIrSi using muon spin relaxation/rotation, J. Phys.: Condens. Matter 32, 085601 (2019)

    2019

  65. [65]

    A. D. Hillier and R. Cywinski, The classification of super- conductors using muon spin rotation, Appl. Magn. Re- son. 13, 95 (1997)

    1997

  66. [66]

    V. K. Anand, A. D. Hillier, D. T. Adroja, A. M. Strydom, H. Michor, K. A. McEwen, and B. D. Rainford, Specific heat and µSR study on the noncentrosymmetric super- conductor LaRhSi 3, Phys. Rev. B 83, 064522 (2011)

    2011

  67. [67]

    Y. J. Uemura, G. M. Luke, B. J. Sternlieb, J. H. Brewer, J. F. Carolan, W. N. Hardy, R. Kadono, J. R. Kempton, R. F. Kiefl, S. R. Kreitzman, P. Mulhern, T. M. Rise- man, D. L. Williams, B. X. Yang, S. Uchida, H. Takagi, J. Gopalakrishnan, A. W. Sleight, M. A. Subramanian, C. L. Chien, M. Z. Cieplak, G. Xiao, V. Y. Lee, B. W. Statt, C. E. Stronach, W. J. K...

    1989

  68. [68]

    Uemura, Classifying superconductors in a plot of Tc versus fermi temperature TF, Physica C 185-189, 733 (1991)

    Y. Uemura, Classifying superconductors in a plot of Tc versus fermi temperature TF, Physica C 185-189, 733 (1991)

    1991

  69. [69]

    Padamsee, J

    H. Padamsee, J. E. Neighbor, and C. A. Shiffman, Quasi- particle phenomenology for thermodynamics of strong- coupling superconductors, J. Low Temp. Phys. 12, 387 (1973)

    1973

  70. [70]

    Johnston, David, Elaboration of the α-model derived from the bcs theory of superconductivity, Supercond

    C. Johnston, David, Elaboration of the α-model derived from the bcs theory of superconductivity, Supercond. Sci. Technol. 26, 115011 (2013)

    2013

  71. [71]

    P. B. Allen and R. C. Dynes, Transition temperature of strong-coupled superconductors reanalyzed, Phys. Rev. B 12, 905 (1975)

    1975

  72. [72]

    E. R. Margine and F. Giustino, Anisotropic migdal- eliashberg theory using wannier functions, Phys. Rev. B 87, 024505 (2013)

    2013

  73. [73]

    S. K. Ghosh, J. F. Annett, and J. Quintanilla, Time- reversal symmetry breaking in superconductors through loop supercurrent order, New J. Phys. 23, 083018 (2021)

    2021

  74. [74]

    Sigrist and K

    M. Sigrist and K. Ueda, Phenomenological theory of un- conventional superconductivity, Rev. Mod. Phys. 63, 239 (1991)

    1991

  75. [75]

    S. K. Ghosh, M. Smidman, T. Shang, J. F. Annett, A. D. Hillier, J. Quintanilla, and H. Yuan, Recent progress on superconductors with time-reversal symmetry breaking, Journal of Physics: Condensed Matter 33, 033001 (2020)

    2020

  76. [76]

    Hao and T

    L. Hao and T. K. Lee, Surface spectral function in the superconducting state of a topological insulator, Phys. Rev. B 83, 134516 (2011)

    2011

  77. [77]

    T. H. Hsieh and L. Fu, Majorana fermions and exotic surface andreev bound states in topological superconduc- tors: Application to CuxBi2Se3, Phys. Rev. Lett. 108, 107005 (2012)

    2012

  78. [78]

    N. S. Mehta, B. Patra, M. Garg, G. Mohmad, M. Mon- ish, P. Bhardwaj, P. K. Meena, K. Motla, R. P. Singh, B. Singh, et al. , Topological surface states host super- conductivity induced by the bulk condensate in YRuB 2, Phys. Rev. B 109, L241104 (2024)

    2024

  79. [79]

    X. P. Yang, Y. Zhong, S. Mardanya, T. A. Cochran, R. Chapai, A. Mine, J. Zhang, J. Sánchez-Barriga, Z.-J. Cheng, O. J. Clark, J.-X. Yin, J. Blawat, G. Cheng, I. Be- lopolski, T. Nagashima, S. Najafzadeh, S. Gao, N. Yao, A. Bansil, R. Jin, T.-R. Chang, S. Shin, K. Okazaki, and M. Z. Hasan, Coexistence of bulk-nodal and surface- nodeless cooper pairings in ...

    2023

  80. [80]

    V. K. Anand, A. D. Hillier, D. T. Adroja, R. Stew- art, Aarti, and K. Panda, Probing superconducting gap structure and time reversal symmetry state of SrPd 2As2 and BaPd 2As2 using muon spin relaxation and rotation (2024), doi: 10.5286/ISIS.E/ISIS.E.RB2410594

    work page doi:10.5286/isis.e/isis.e.rb2410594 2024

Showing first 80 references.