Spontaneous Nernst effect in the iron-based superconductor 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Fe</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>+</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Se</mml:mi><mml:mi>x</mml:mi></mml:msub></mml:mrow></mml:math>

Chen, Lu; Xiang, Ziji; Tinsman, Colin; Lei, Bin; Chen, Xianhui; Gu, Genda; Li, Lü

doi:10.1103/physrevb.102.054503

Cited by 7 publications

(5 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such vortices, dubbed quantum anomalous vortices, support robust Majorana zero modes when superconductivity is induced in the topological surface states. The existence of quantum anomalous vortices at native interstitial Fe impurities is also consistent with the spontaneous Nernst signal in thermal transport measurement 160 . The quantum anomalous vortex appears to be a more robust way to generate Majorana zero modes than the field-induced vortex method 152 , as the topologically trivial vortex state is pushed to higher energies.…”

Section: Topological Correspondencesupporting

confidence: 81%

Probing topological quantum matter with scanning tunnelling microscopy

2021

View full text Add to dashboard Cite

The search for topological phases of matter is evolving towards strongly interacting systems, including magnets and superconductors, where exotic effects emerge from the quantum-level interplay between geometry, correlation and topology. Over the past decade or so, scanning tunnelling microscopy has become a powerful tool to probe and discover emergent topological matter, because of its unprecedented spatial resolution, high-precision electronic detection and magnetic tunability. Scanning tunnelling microscopy can be used to probe various topological phenomena, as well as complement results from other techniques. We discuss some of these proofof-principle methodologies applied to probe topology, with particular attention to studies performed under a tunable vector magnetic field, which is a relatively new direction of recent focus. We then project the future possibilities for atomic-resolution tunnelling methods in providing new insights into topological matter. Key points• Explorations of quasi-particle interference and Landau quantization behaviours in materials can be used to elucidate the nature of chiral or helical fermions and their interplay with symmetrybreaking order, such as magnetism, charge order or superconductivity. • Bulk-boundary connectivity and its relationship with atomically resolved lattice and magnetic structure probed via topographic measurements are central to understanding emergent topology, such as in kagome lattices. • Tunable vector magnetic field capability allows for exploring field-induced novel states in topological matter, including emergent magnetism, superconductivity and strongly correlated phases. • In the presence of magnetic field control, spectro-microscopy plays an important role in identifying the nature of localized zero modes or in-gap states, such as the Majorana mode. • Scanning tunnelling microscopy-based study on topological materials can be further extended for visualizing Wannier-Bloch duality and can be employed in sub-nanoscale engineering in developing quantum information science platforms.

show abstract

Section: Topological Correspondencesupporting

confidence: 81%

Probing topological quantum matter with scanning tunnelling microscopy

2021

View full text Add to dashboard Cite

show abstract

“…1c, in agreement with the previous electrical transport study (see Supporting Information Section 1 for details). 10 We first employed NV wide-field microscopy [28][29][30] to perform Rabi oscillation measurements to image circular AC supercurrents in the FTS flake. An NV center is formed by a nitrogen atom adjacent to a carbon atom vacancy in one of the nearest neighboring sites of a diamond crystal lattice.…”

Section: Methodsmentioning

confidence: 99%

“…TRSB pairing symmetries have been theoretically proposed in iron-based superconductors. 9 Experimentally, thermal transport and angle-resolved photoemission spectroscopy studies suggest the spontaneous TRSB and opening of a band gap at the surface Dirac cone in superconducting FeTexSe1-x, 10,11 which indicates the presence of ferromagnetism induced by an intrinsic unconventional pairing symmetry. 12 The interplay among topology, 4,6,8,13 superconductivity, 4,7 and magnetism 10,11 makes FeTexSe1-x an attractive platform to explore a range of emergent quantum spin and charge transport phenomena.…”

Section: Introductionmentioning

confidence: 99%

“…9 Experimentally, thermal transport and angle-resolved photoemission spectroscopy studies suggest the spontaneous TRSB and opening of a band gap at the surface Dirac cone in superconducting FeTexSe1-x, 10,11 which indicates the presence of ferromagnetism induced by an intrinsic unconventional pairing symmetry. 12 The interplay among topology, 4,6,8,13 superconductivity, 4,7 and magnetism 10,11 makes FeTexSe1-x an attractive platform to explore a range of emergent quantum spin and charge transport phenomena. 11,[14][15][16] Despite remarkable progress, detailed knowledge of the local magnetic properties of superconducting FeTexSe1-x remains elusive, and direct evidence to corroborate the coexistence of superconductivity and ferromagnetism in FeTexSe1-x is still lacking.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Strong Correlation Between Superconductivity and Ferromagnetism in an Fe-Chalcogenide Superconductor

et al. 2021

View full text Add to dashboard Cite

The interplay among topology, superconductivity, and magnetism promises to bring a plethora of exotic and unintuitive behaviors in emergent quantum materials. The family of Fechalcogenide superconductors FeTexSe1-x are directly relevant in this context due to their intrinsic topological band structure, high-temperature superconductivity, and unconventional pairing symmetry. Despite enormous promise and expectation, the local magnetic properties of FeTexSe1x remain largely unexplored, which prevents a comprehensive understanding of their underlying material properties. Exploiting nitrogen vacancy (NV) centers in diamond, here we report nanoscale quantum sensing and imaging of magnetic flux generated by exfoliated FeTexSe1-x flakes, providing clear evidence of superconductivity-induced ferromagnetism in FeTexSe1-x. The coexistence of superconductivity and ferromagnetism in an established topological superconductor opens up new opportunities for exploring exotic spin and charge transport phenomena in quantum materials. The demonstrated coupling between NV centers and FeTexSe1-x may also find applications in developing hybrid architectures for next-generation, solid-state-based quantum information technologies.

show abstract

“…After removal of 𝐵 𝐶𝑜𝑜𝑙𝑖𝑛𝑔 , a small fraction of vortices can still be trapped at pinning sites, resulting in Kerr signals during ZFW. In fact, we speculate that motions of trapped vortices under thermal gradients may account for the reported spontaneous Nernst signal [28] in FeTe1-xSex. Since 𝐻 𝐶1 of 4 𝑚𝑇 [29] is smaller than the coercive field, in this sample trainings involve trapped vortices.…”

mentioning

confidence: 79%

Revealing the Origin of Time-Reversal Symmetry Breaking in Fe-Chalcogenide Superconductor FeTe1−xSex

et al. 2023

View full text Add to dashboard Cite

Recently evidence has emerged in the topological superconductor Fe-chalcogenide FeTe1-xSex for time-reversal symmetry breaking (TRSB), the nature of which has strong implications on the Majorana zero modes (MZM) discovered in this system. It remains unclear however whether the TRSB resides in the topological surface state (TSS) or in the bulk, and whether it is due to an unconventional TRSB superconducting order parameter or an intertwined order. Here by performing in superconducting FeTe1-xSex crystals both surface-magneto-optic-Kerr effect (SMOKE) measurements using a Sagnac interferometer and bulk magnetic susceptibility measurements, we pinpoint the TRSB to the TSS, where we also detect a Dirac gap. Further, we observe surface TRSB in non-superconducting FeTe1-xSex of nominally identical composition, indicating that TRSB arises from an intertwined surface ferromagnetic (FM) order. The observed surface FM bears striking similarities to the two-dimensional (2D) FM found in 2D van der Waals crystals, and is highly sensitive to the exact chemical composition, thereby providing a means for optimizing the conditions for Majorana particles that are useful for robust quantum computing.

show abstract

Spontaneous Nernst effect in the iron-based superconductor Fe1+yTe1−xSex

Cited by 7 publications

References 64 publications

Probing topological quantum matter with scanning tunnelling microscopy

Probing topological quantum matter with scanning tunnelling microscopy

Strong Correlation Between Superconductivity and Ferromagnetism in an Fe-Chalcogenide Superconductor

Revealing the Origin of Time-Reversal Symmetry Breaking in Fe-Chalcogenide Superconductor FeTe1−xSex

Contact Info

Product

Resources

About