Edge States at Nematic Domain Walls in FeSe Films

Yuan, Yonghao; Li, Wei; Liu, Bin; Deng, Peng; Chen, Xi; Song, Can-Li; Wang, Lili; He, Ke; Xu, Gang; Ma, Xu-Cun; Xue, Qi‐Kun

doi:10.1021/acs.nanolett.8b03282

Cited by 17 publications

(30 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…STS measurements show the existence of edge states along [100] and [1

\overset{1}{true}

0] directions . Similar edge states are also reported in the domain boundaries of FeSe . Freestanding monolayer FeSe is predicted to be an intrinsic AFM QSH insulator, which means that the Fermi surface is in the SOC gap.…”

Section: Quantum Spin Hall Effect In Layered Materials and Thin Filmssupporting

confidence: 75%

Quantum Spin Hall Materials

Cao

Chen

2019

Adv Quantum Tech

View full text Add to dashboard Cite

The quantum spin Hall (QSH) effect describes the state of matter in certain 2D electron systems, in which an insulating bulk state arises together with helical states at the edge of the sample. In stark contrast to its closest kin, the integer quantum Hall state, the QSH state exists only in time‐reversal symmetric system (e.g., in non‐magnetic materials and without the application of external magnetic field). This article reviews the development of the understanding and construction of the QSH states after their first theoretical proposal, with an emphasis on the materials perspective. Certain semiconductor quantum wells and 2D materials with strong spin–orbit coupling have been found to support QSH states.

show abstract

“…STS measurements show the existence of edge states along [100] and [1

\overset{1}{true}

Section: Quantum Spin Hall Effect In Layered Materials and Thin Filmssupporting

confidence: 75%

Quantum Spin Hall Materials

Cao

Chen

2019

Adv Quantum Tech

View full text Add to dashboard Cite

show abstract

“…These, however, were relatively far below the Fermi level. A more recent study focused on domain walls between different nematic domains in multi-layer FeSe/STO [382].…”

Section: Experimental Evidence For Topological Bandsmentioning

confidence: 99%

“…As a consequence, if π phase shift domain walls could be generated on the surface of topological FeSCs, 1D Majorana modes could exist along the domain walls. Above, we briefly mentioned an STM study of nematic domain walls in 20 unit-cell thick FeSe on STO, interpreted in the light of 1D dispersing topological edge states [382]. Unlike monolayers, the multilayer films are known to feature strong electronic nematicity.…”

Section: One-dimensional Dispersive Majorana Modesmentioning

confidence: 99%

“…Unlike monolayers, the multilayer films are known to feature strong electronic nematicity. Specifically, Yuan et al [382] grew 20 unit cell thick FeSe films on top of STO substrates, and studied the electronic states near domain walls between two distinct nematic regions. The resulting STS data found evidence for edge-induced zero-energy states localized to the domain walls, and interpreted them in terms of topological edge modes [382].…”

Section: One-dimensional Dispersive Majorana Modesmentioning

confidence: 99%

See 1 more Smart Citation

On the Remarkable Superconductivity of FeSe and Its Close Cousins

2020

View full text Add to dashboard Cite

Emergent electronic phenomena in iron-based superconductors have been at the forefront of condensed matter physics for more than a decade. Much has been learned about the origins and intertwined roles of ordered phases, including nematicity, magnetism, and superconductivity, in this fascinating class of materials. In recent years, focus has been centered on the peculiar and highly unusual properties of FeSe and its close cousins. This family of materials has attracted considerable attention due to the discovery of unexpected superconducting gap structures, a wide range of superconducting critical temperatures, and evidence for nontrivial band topology, including associated spin-helical surface states and vortex-induced Majorana bound states. Here, we review superconductivity in iron chalcogenide superconductors, including bulk FeSe, doped bulk FeSe, FeTe1−xSex, intercalated FeSe materials, and monolayer FeSe and FeTe1−xSex on SrTiO3. We focus on the superconducting properties, including a survey of the relevant experimental studies, and a discussion of the different proposed theoretical pairing scenarios. In the last part of the paper, we review the growing recent evidence for nontrivial topological effects in FeSe-related materials, focusing again on interesting implications for superconductivity.

show abstract

“…In bulk single crystals, the spatial extent of electronic nematic domains is typically at the order of a few micrometers 11,14,23,26,27 . In certain thin films however, the domain size is found to be significantly reduced compared to their bulk counterparts 21,28 . For example, while the domain size in FeSe single crystals is several micrometers 14,23 , it is reduced to~10 nm length scales in thin films 21,28 .…”

mentioning

confidence: 93%

Nanoscale decoupling of electronic nematicity and structural anisotropy in FeSe thin films

Ren

Zhao

et al. 2021

Nat Commun

View full text Add to dashboard Cite

In a material prone to a nematic instability, anisotropic strain in principle provides a preferred symmetry-breaking direction for the electronic nematic state to follow. This is consistent with experimental observations, where electronic nematicity and structural anisotropy typically appear hand-in-hand. In this work, we discover that electronic nematicity can be locally decoupled from the underlying structural anisotropy in strain-engineered iron-selenide (FeSe) thin films. We use heteroepitaxial molecular beam epitaxy to grow FeSe with a nanoscale network of modulations that give rise to spatially varying strain. We map local anisotropic strain by analyzing scanning tunneling microscopy topographs, and visualize electronic nematic domains from concomitant spectroscopic maps. While the domains form so that the energy of nemato-elastic coupling is minimized, we observe distinct regions where electronic nematic ordering fails to flip direction, even though the underlying structural anisotropy is locally reversed. The findings point towards a nanometer-scale stiffness of the nematic order parameter.

show abstract

Edge States at Nematic Domain Walls in FeSe Films

Cited by 17 publications

References 47 publications

Quantum Spin Hall Materials

Quantum Spin Hall Materials

On the Remarkable Superconductivity of FeSe and Its Close Cousins

Nanoscale decoupling of electronic nematicity and structural anisotropy in FeSe thin films

Contact Info

Product

Resources

About