Symmetry constraints on the elastoresistivity tensor

Shapiro, M. C.; Hlobil, Patrik; Hristov, Alexander T.; Maharaj, Akash V.; Fisher, I. R.

doi:10.1103/physrevb.92.235147

Cited by 33 publications

(41 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a measure of the thermodynamic nematic susceptibility, elastoresistive measurements were taken across the Ba 1−x Sr x Ni 2 As 2 phase diagram. Within the D 4h point group, elastoresistive coefficient m 12 − m 11 are directly proportional to χ B1g nem while m 66 is directly proportional to χ B2g nem [38]. Both m 12 − m 11 and m 66 were measured in samples adhered directly to a lead-zirconiumtitanate (PZT) piezoelectric stack using a strain transmitting epoxy as discussed in Refs.…”

Section: Elastoresistivitymentioning

confidence: 99%

Sixfold enhancement of superconductivity in a tunable electronic nematic system

et al. 2019

View full text Add to dashboard Cite

The electronic nematic phase, wherein electronic degrees of freedom lower the crystal rotational symmetry, is a common motif across a number of high-temperature superconductors. However, understanding the role and influence of nematicity and nematic fluctuations in Cooper pairing is often complicated by the coexistence of other orders, particularly long-range magnetic order. Here we report the enhancement of superconductivity in a model electronic nematic system absent of magnetism, and show that the enhancement is directly born out of strong nematic fluctuations emanating from a tuned quantum phase transition. We use elastoresistance measurements of the Ba1−xSrxNi2As2 substitution series to show that strontium substitution promotes an electronically driven B1g nematic order in this system, and that the complete suppression of that order to absolute zero temperature evokes a dramatic enhancement of the pairing strength, as evidenced by a sixfold increase in the superconducting transition temperature. The direct relation between enhanced pairing and nematic fluctuations in this model system, as well as the interplay with a unidirectional charge density wave order comparable to that found in the cuprates, offers a means to elucidate the role of nematicity in boosting superconductivity. I.High-temperature superconductivity in both cuprate [1, 2] and iron-based materials [3-5] emerges from a notably complex normal state. Though magnetic spin fluctuations are commonly believed to drive Cooper pairing in both of these families, the common occurrence of a rotational symmetry-breaking nematic phase has captured increasing attention in recent years [6,7]. In contrast to a conventional structural transition, overwhelming evidence suggests that the nematic phase in these compounds is promoted by an electronic instability rather than lattice softening [8,9].Theoretical analyses have shown that fluctuations associated with such an electronic nematic phase, particularly near a putative quantum critical point, can significantly enhance superconductivity [10][11][12][13][14]. Being peaked at zero wave-vector, nematic fluctuations favor pairing instabilities in several symmetry channels, in contrast to the case of magnetic fluctuations. Experiments have indeed shown a striking enhancement of nematic fluctuations centered at optimal tuning of superconductivity in a number of iron-based superconductors [8,9], and a strong tendency towards nematicity in high T c cuprate materials [15][16][17]. However, the overarching presence of magnetic fluctuations emanating from proximate antiferromagnetic instabilities complicates drawing any isolated relation between enhanced pairing and nematicity in most nematic materials. The FeSe 1−x S x substitution series is one exception, where the system exhibits both superconductivity and nematicity in the absence of magnetic order [18]. However, in this series, the superconducting transition temperature T c is virtually unaffected by tuning through the nematic quantum critical point [18,19], leaving ...

show abstract

Section: Elastoresistivitymentioning

confidence: 99%

Sixfold enhancement of superconductivity in a tunable electronic nematic system

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The definition of the base resistance R 0 used to normalize the elastoresistivity response carries some ambiguity. 29 If the physical origin of the magnetoresistance of Ba(Fe 1−x Co x ) 2 As 2 were independent of nematic fluctuations, the most physically motivated choice would be to normalize by the extrapolated zero field resistance.…”

Section: Appendix A: Normalization Of Resistivity Ratiosmentioning

confidence: 99%

Growth of nematic susceptibility in the field-induced normal state of an iron-based superconductor revealed by elastoresistivity measurements in a 65 T pulsed magnet

et al. 2019

Self Cite

View full text Add to dashboard Cite

In the iron-based superconductors, both nematic and magnetic fluctuations are expected to enhance superconductivity and may originate from a quantum critical point hidden beneath the superconducting dome. The behavior of the non-superconducting state can be an important piece of the puzzle, motivating in this paper the use of high magnetic fields to suppress superconductivity and measure the nematic susceptibility of the normal state at low temperatures. We describe experimental advances which make it possible to measure a resistive gauge factor (which is a proxy for the nematic susceptibility) in the field-induced normal state in a 65 T pulsed magnet, and report measurements of the gauge factor of a micromachined single crystal of Ba(Fe0.926Co0.074)2As2 at temperatures down to 1.2 K. The nematic susceptibility increases monotonically in the field-induced normal state as the temperature decreases, consistent with the presence of a quantum critical point nearby in composition. :1907.12191v1 [cond-mat.str-el] arXiv

show abstract

“…Experimental evidence for nematic response was first obtained in the BaFe 2 As 2 system [10][11][12][13][14][15], where a structural transition that lowers the rotational symmetry from C 4 to C 2 is closely followed by antiferromagnetic ordering [16][17][18], with modulation wave vector (π, 0) [19]. New interest has been generated by the recent observations of nematicity in FeSe [20], a superconducting compound that exhibits a symmetry-lowering structural transition but no magnetic order [21,22].…”

Section: Introductionmentioning

confidence: 99%

Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconductingFeTe1−xSex

Schneeloch

Wen

et al. 2016

Phys. Rev. B

View full text Add to dashboard Cite

It has recently been demonstrated that dynamical magnetic correlations measured by neutron scattering in iron chalcogenides can be described with models of short-range correlations characterized by particular choices of four-spin plaquettes, where the appropriate choice changes as the parent material is doped towards superconductivity. Here we apply such models to describe measured maps of magnetic scattering as a function of two-dimensional wave vectors obtained for optimally superconducting crystals of FeTe1−xSex. We show that the characteristic antiferromagnetic wave vector evolves from that of the bicollinear structure found in underdoped chalcogenides (at high temperature) to that associated with the stripe structure of antiferromagnetic iron arsenides (at low temperature); these can both be described with the same local plaquette, but with different inter-plaquette correlations. While the magnitude of the low-energy magnetic spectral weight is substantial at all temperatures, it actually weakens somewhat at low temperature, where the charge carriers become more itinerant. The observed change in spin correlations is correlated with the dramatic drop in the electronic scattering rate and the growth of the bulk nematic response on cooling. Finally, we also present powder neutron diffraction results for lattice parameters in FeTe1−xSex indicating that the tetrahedral bond angle tends to increase towards the ideal value on cooling, in agreement with the increased screening of the crystal field by more itinerant electrons and the correspondingly smaller splitting of the Fe 3d orbitals.

show abstract

Symmetry constraints on the elastoresistivity tensor

Cited by 33 publications

References 12 publications

Sixfold enhancement of superconductivity in a tunable electronic nematic system

Sixfold enhancement of superconductivity in a tunable electronic nematic system

Growth of nematic susceptibility in the field-induced normal state of an iron-based superconductor revealed by elastoresistivity measurements in a 65 T pulsed magnet

Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconductingFeTe1−xSex

Contact Info

Product

Resources

About