Superconductivity and magnetic order in a strongly interacting fermi-system: URu2Si2

Schlabitz, W.; Baumann, J.; Pollit, B.; Rauchschwalbe, U.; Mayer, H. M.; Ahlheim, U.; Bredl, C. D.

doi:10.1007/bf01323427

Cited by 514 publications

(282 citation statements)

References 28 publications

Supporting

Mentioning

263

Contrasting

Order By: Relevance

“…This is a consequence of multi-band superconductivity with compensated electronic structure in the hidden order state of this system. We provide strong evidence for a new type of unconventional superconductivity with two distinct gaps having different nodal topology.The heavy-Fermion compound URu 2 Si 2 has mystified researchers since the superconducting state (T c = 1.5 K) is embedded within the "hidden order" phase (T h = 17.5 K) [1,2,3]. Although several exotic order parameters have been proposed for the hidden order phase [4], it is not identified yet.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Exotic Superconducting Properties in the Electron-Hole-Compensated Heavy-Fermion “Semimetal”URu2Si2

et al. 2007

View full text Add to dashboard Cite

We show that the charge and thermal transport measurements on ultraclean crystals of URu2Si2 reveal a number of unprecedented superconducting properties. The uniqueness is best highlighted by the peculiar field dependence of thermal conductivity including the first order transition at Hc2 with a reduction of entropy flow. This is a consequence of multi-band superconductivity with compensated electronic structure in the hidden order state of this system. We provide strong evidence for a new type of unconventional superconductivity with two distinct gaps having different nodal topology.The heavy-Fermion compound URu 2 Si 2 has mystified researchers since the superconducting state (T c = 1.5 K) is embedded within the "hidden order" phase (T h = 17.5 K) [1,2,3]. Although several exotic order parameters have been proposed for the hidden order phase [4], it is not identified yet. According to several experimental observations, most of the carriers disappear below T h resulting in a density one order of magnitude smaller than in other heavy-Fermion superconductors [5,6,7]. Superconductivity with such a low density is remarkablesince the superfluid density is very low in some way reminiscent of underdoped cuprates. Moreover, pressure studies reveal that the superconductivity coexists with the hidden order but is suppressed by antiferromagnetic ordering [8].In this Letter, using ultraclean single crystals, we report various anomalous superconducting properties in URu 2 Si 2 . We show that a peculiar electronic structure appearing below the hidden order transition provides an intriguing stage on which a new type of unconventional superconducting state appears.Single crystals of URu 2 Si 2 were grown by the Czochralski pulling method in a tetra-arc furnace. The welldefined superconducting transition was confirmed by the specific heat measurements. The thermal conductivity κ was measured using a standard four-wire steady state method along the a-axis (heat current q a). The contact resistance at low temperatures is less than 10 mΩ.We first discuss the electronic structure below T h . Figure 1 shows the temperature dependence of the resistivity ρ along the a-axis and Hall coefficient R H (solid circles) defined as R H ≡ dρxy dH at H → 0 T for H c in the tetragonal crystal structure. In zero field, ρ depends on T as ρ = ρ 0 + AT 2 below 6 K down to T c . The exceptionally low residual resistivity ρ 0 = 0.48 µΩ cm and large residual resistivity ratio RRR = 670 attest the highest crystal quality currently achievable. R H exhibits an eight-fold increase below T h and attains a T -independent value at low temperatures, associated with a strong reduction of the carrier density. Most remarkably, the magnetoresistance (MR) increases with decreasing temperature and becomes extremely large at the lowest temperatures. The inset of Fig.

show abstract

mentioning

confidence: 99%

“…The heavy-Fermion compound URu 2 Si 2 has mystified researchers since the superconducting state (T c = 1.5 K) is embedded within the "hidden order" phase (T h = 17.5 K) [1,2,3]. Although several exotic order parameters have been proposed for the hidden order phase [4], it is not identified yet.…”

mentioning

confidence: 99%

Exotic Superconducting Properties in the Electron-Hole-Compensated Heavy-Fermion “Semimetal”URu2Si2

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Although the microscopic order parameter has not yet been definitively established, a multitude of bulk property measurements indicate that a partial gapping of the Fermi surface is involved in the HO transition. In addition to the BCS-like specific heat anomaly, there are anomalies in the electrical resistivity, magnetic susceptibility [77][78][79], ultrasound [86], thermal expansion [87], and an increase in lattice thermal conductivity [88]. Additional evidence points to the opening of a large gap in the tunneling spectrum [89], the incommensurate spin excitation spectrum [90], and the crossing of the chemical potential by a heavy electron band [91].…”

Section: Uru 2 Simentioning

confidence: 99%

“…Both the magnetic susceptibility and electrical resistivity are anisotropic [78,79], and show characteristics typical of Kondo lattice materials. The magnetic susceptibility χ(T ) follows a Curie-Weiss law at high temperatures, reflecting a uranium free ion moment, but deviates from this behavior above 100 K and peaks at 50 K. At low temperatures, χ(T ) saturates to a value of χ 0 ≈ 0.005 cm 3 mol −1 .…”

Section: Uru 2 Simentioning

confidence: 99%

“…The heavy fermion compound URu 2 Si 2 undergoes two ordering transitions: below about 1.5 K it is a superconductor, while at higher temperatures but below 17.5 K, it is in a hidden order (HO) phase [77][78][79]. The latter ordered phase has been the subject of much attention and disagreement over the more than two decades since the discovery of the compound.…”

Section: Uru 2 Simentioning

confidence: 99%

See 1 more Smart Citation

Non-Fermi Liquid Regimes and Superconductivity in the Low Temperature Phase Diagrams of Strongly Correlated d- and f-Electron Materials

et al. 2010

View full text Add to dashboard Cite

Standard models for simple metals and insulators often fail for systems based on elements with unstable d-or f -electron shells, where strong electronic correlations can generate new and unexpected states of matter. Such a scenario can often be induced when a magnetic phase transition is tuned to absolute zero temperature by an external control parameter such as chemical composition, pressure or magnetic field. At the resulting quantum critical point (QCP), emergent phenomena, such as unconventional superconductivity and novel magnetic phases are frequently observed. The temperature and energy dependences of the physical properties are also found to deviate from expectations for a simple Fermi liquid. This "non-Fermi-liquid" (NFL) behavior is commonly manifested as weak power laws and logarithmic divergences in the physical properties at low temperatures and is often found in a V-shaped region near a QCP, which has become the "classic" QCP phase diagram. However, there is also a growing number of materials where the NFL behavior either occurs far away from the QCP, within an ordered phase, or may not be associated with any putative QCP. Thus, after nearly 20 years of research, it remains unknown whether NFL physics is universal, or if a multitude of unique subclasses exist. In this article, we review research that has primarily been carried out in our laboratory on systems that exhibit NFL behavior that does not conform to the "classic" QCP scenario.

show abstract

Review on Superconducting Materials

Hott

Kleiner

Wolf

et al. 2016

Digital Encyclopedia of Applied Physics

View full text Add to dashboard Cite

The article contains sections titled: Introduction Cuprate High‐Temperature Superconductors Other Oxide Superconductors Iron‐Based Superconductors Other Chalcogenide Superconductors Heavy Fermion Superconductors Nitride Superconductors Organic and Other Carbon‐ and Silicon‐Based Superconductors Borides and Borocarbides

show abstract

Superconductivity and magnetic order in a strongly interacting fermi-system: URu2Si2

Cited by 514 publications

References 28 publications

Exotic Superconducting Properties in the Electron-Hole-Compensated Heavy-Fermion “Semimetal”URu2Si2

Exotic Superconducting Properties in the Electron-Hole-Compensated Heavy-Fermion “Semimetal”URu2Si2

Non-Fermi Liquid Regimes and Superconductivity in the Low Temperature Phase Diagrams of Strongly Correlated d- and f-Electron Materials

Review on Superconducting Materials

Contact Info

Product

Resources

About