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Superconductivity in Unconventional Metals and its Interplay with Magnetism

English title Superconductivity in Unconventional Metals and its Interplay with Magnetism
Applicant Gavilano Jorge Luis
Number 147071
Funding scheme Project funding (Div. I-III)
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Condensed Matter Physics
Start/End 01.10.2013 - 30.09.2017
Approved amount 240'683.00
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Keywords (8)

Heavy Fermion; charge density wave; unconventional superconductivity; Magnetism; spin density wave; neutron scattering; Quantum critical point; SANS

Lay Summary (German)

Lead
Wir planen experimentelle Studien des Verhaltens von unkonventionellen Supraleiter und europäischen Grossforschungsanlagen wie dem SINQ am PSI.
Lay summary

Inhalt und Ziel des Forschungsprojekts

Im Zentrum unseres Forschungsprojekts stehen von unkonventionellen Supraleitern. Hierbei handelt es sich um Materialien, deren metallische Eigenschaften sich schon im Normalzustand, sich deutlich von deren "normaler" Metalle unterscheiden. Die Ladungsträger in diesen Verbindungen verhalten ich nicht wie freie Leitungselektronen, denn starke Elektron-Elektron Wechselwirkungen dominieren die Physik. Diese Wechselwirkungen führen bereits im Normalzustand zu Phasenübergängen zu sogenannten Ladungs- oder Spindichtewellen welche mit einer Änderung der elektronischen Struktur einhergehen. Bei tiefen Temperaturen wird zudem oft der Übergang zu einem sogenannten Schweren Fermion Verhalten beobachtet. Auf Grund der Wechselwirkungen verhalten sich die Elektronen in einem solchen System, also ob ihre Masse 100 bis 1000 mal schwerer ist als die eigentliche Elektronenmasse. Man kann diesen Zustand leicht durch einen äusseren Parameter wie das Magnetfeld, hydrostatischem Druck oder durch schwache chemische Substitution beeinflussen. Durch stetiges Erhöhen dieses äusseren Parameters bis zu einem kritischen Wert kann das Elektronensystem in einen neuen Zustand übergeführt werden, in dem die Physik dann durch Quantenfluktuationen bestimmt ist.

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Starke Korrelationen sind eines der grossen ungelösten Probleme in der Physik. In der Vergangenheit haben Untersuchungen der Supraleitung wiederholt zu grossen Durchbrüchen in der Physik geführt: Von technischen Anwendung wie der Kernspinresonanz bis zu Durchbrüchen in der Theorie der Elektron-Phonenwechselwirkung. Wir erachten unkonventionelle Supraleiter als ideale Systeme um starke Wechselwirkungen zu untersuchen.

Direct link to Lay Summary Last update: 27.09.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Spin Resonance and Magnetic Order in an Unconventional Superconductor
Mazzone Daniel et al. (2017), Spin Resonance and Magnetic Order in an Unconventional Superconductor, in Phys. Rev. Lett, 199(18), 187002-1-187002-5.
Field induced magnetic instability within a superconducting condensate
Mazzone Daniel et al. (2017), Field induced magnetic instability within a superconducting condensate, in SCIENCE ADVANCES, (5 ), e1602055.
Fully gapped superconductivity in the topological superconductor beta-PdBi2
Biswas Pabitra et al. (2016), Fully gapped superconductivity in the topological superconductor beta-PdBi2, in PHYSICAL REVIEW B, 93(22), 220504.
Crystal structure and phonon softening in Ca3Ir4Sn13
Mazzone Daniel et al. (2015), Crystal structure and phonon softening in Ca3Ir4Sn13, in PHYSICAL REVIEW B, 92(2), 024101.
Distinct vortex-glass phases in Yb3Rh4Sn13 at high and low magnetic fields
Mazzone Daniel et al. (2015), Distinct vortex-glass phases in Yb3Rh4Sn13 at high and low magnetic fields, in OURNAL OF PHYSICS-CONDENSED MATTER , 27(24), 245701.
New structures formed by R3Au4Sn3, R5Au8Sn5 and R3Au6Sn5 compounds (R = rare earths)
Fornassini M.L. et al. (2014), New structures formed by R3Au4Sn3, R5Au8Sn5 and R3Au6Sn5 compounds (R = rare earths), in Intermetallics, 63, 169.
Small angle neutron scattering study oft he mixed state of Yb3Rh4Sn13
Mazzone Daniel et al. (2014), Small angle neutron scattering study oft he mixed state of Yb3Rh4Sn13, in Phys. Rev. B, 90(2), 02507.
Distinct domain switching in Nd$_{0.05}$Ce$_{0.95}$CoIn$_5$ at low and high fields
Mazzone Daniel et al., Distinct domain switching in Nd$_{0.05}$Ce$_{0.95}$CoIn$_5$ at low and high fields, in Scientific Reports.

Collaboration

Group / person Country
Types of collaboration
Prof. K. Conder /LDM / PSI Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Prof. Andrea Bianchi / Physics Dept./ University of Montreal/ Canada Canada (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
International Conference on Neutron Scattering, Daejeon, Korea, Talk given at a conference Evidence for a novel quantum phase transition 09.07.2017 Daejeon, Korean Republic (South Korea) Gavilano Jorge Luis; Kenzelmann Michel; Mazzone Daniel Gabriel;
Seminar Individual talk Evidence for a novel quantum phase transition 02.03.2017 Stockholm, Sweden Mazzone Daniel Gabriel;
Quantum Criticality and Novel Phases 2017 Talk given at a conference Possible quantum critical point in Nd-doped CeCoIn5 27.02.2017 Berlin, Germany Mazzone Daniel Gabriel;
20 years SINQ/PSI Talk given at a conference Discovery of a superconducting quantum critical point 04.01.2017 Villigen Switzerland, Switzerland Mazzone Daniel Gabriel;
30th Meeting of the European Crystallographic Association, Basel, Switzerland, Poster Complete decoupling of magnetic order and superconductivity in a conventional superconductor 28.08.2016 Basel, Switzerland Gavilano Jorge Luis; Mazzone Daniel Gabriel; Kenzelmann Michel;
Annual meeting of the Swiss Physical Society Talk given at a conference Discovery of a superconducting quantum critical point 23.08.2016 Lugano, Switzerland Kenzelmann Michel; Mazzone Daniel Gabriel; Gavilano Jorge Luis;
FFLO Phase in Quantum Liquids, Quantum Gases, and Nuclear Matter Talk given at a conference A superconducting quantum critical point at the origin of the spin6triplet pair density6wave order in the Q-phase 23.06.2016 Dreasden, Germany Mazzone Daniel Gabriel;
seminar Individual talk Unconventional interplay between magnetism and superconductivity in Pr2Pt3Ge5 and Nd0.05Ce0.95CoIn5 20.05.2016 Villigen PSI, Switzerland Mazzone Daniel Gabriel;
seminar Individual talk Evidence for a novel quantum phase transition 11.01.2016 Milan, Italy Mazzone Daniel Gabriel;
seminar Individual talk Complete decoupling of magnetic order and superconductivity in a conventional superconductor 10.11.2015 Villigen PSI, Switzerland Mazzone Daniel Gabriel;
International Conference on Strongly Correlated Electron Systems Talk given at a conference Discovery of a superconducting quantum critical point 10.11.2015 Hanzhou, China Gavilano Jorge Luis; Kenzelmann Michel; Mazzone Daniel Gabriel;
6th European Conference on Neutron Scattering Poster Complete decoupling of magnetic order and superconductivity in a conventional superconductor 30.08.2015 Zaragoza, Spain Gavilano Jorge Luis; Kenzelmann Michel; Mazzone Daniel Gabriel;
6th European Conference on Neutron Scattering Talk given at a conference Distinct interplay between magnetism and superconductivity in NdxCe16xCoIn5 30.08.2015 Zaragoza , Spain Mazzone Daniel Gabriel; Kenzelmann Michel; Gavilano Jorge Luis;
11th Materials and Mechanisms of Superconductivity 2015 Poster Complete decoupling of magnetic order and superconductivity in a conventional superconductor 23.08.2015 Geneva, Switzerland Mazzone Daniel Gabriel; Gavilano Jorge Luis; Kenzelmann Michel;
11th Materials and Mechanisms of Superconductivity 2015 Poster Distinct interplay between magnetism and superconductivity in NdxCe16xCoIn5 23.08.2015 Geneva, Switzerland Mazzone Daniel Gabriel; Gavilano Jorge Luis; Kenzelmann Michel;
20th International Conference on magnetism Poster Distinct interplay between magnetism and superconductivity in NdxCe16xCoIn5 05.07.2015 Barcelona, Spain Mazzone Daniel Gabriel; Gavilano Jorge Luis; Kenzelmann Michel;
13th International Conference on Muon Spin Rotation, Relaxation and Resonance Poster Study of the superconducting state of β6Bi2Pd 02.06.2014 Grindelwald, Switzerland Gavilano Jorge Luis; Kenzelmann Michel; Mazzone Daniel Gabriel;
HERCULES school 2014 Poster Phase transitions in ternary intermetallic stannides 23.02.2014 Grenoble and Saclay, France Kenzelmann Michel; Mazzone Daniel Gabriel; Gavilano Jorge Luis;
Annual meeting of the Swiss Physical Society, Poster A neutron scattering study of the mixed state of Yb3Rh4Sn13 30.01.2014 Fribourg, Switzerland Mazzone Daniel Gabriel; Gavilano Jorge Luis; Kenzelmann Michel;


Associated projects

Number Title Start Funding scheme
140345 Interplay of Magnetism and Superconductivity in Unconventional Superconductors 01.04.2012 Project funding (Div. I-III)
170773 A new high efficiency two-dimensional neutron detector for the cold-neutron diffractometer DMC at SINQ 01.11.2017 R'EQUIP
122054 Interplay of Magnetism and Superconductivity in Unconventional Superconductors 01.04.2009 Project funding (Div. I-III)
150713 ZEBRA - a new neutron single-crystal diffractometer optimized for small samples and extreme conditions 01.11.2014 R'EQUIP

Abstract

We request funding for two Ph.D. students to experimentally study superconductivity in unconventional metals and its interplay with magnetism. The superconducting (SC) systems of our interest are materials displaying heavy-fermion phenomena and/or Fermi surface instabilities, such as charge density wave (CDW) and spin-density wave (SDW). The physical properties of these systems are governed by strong electron-electron correlations, for which there is no microscopic description. Unconventional superconductivity develops from a paramagnetic heavy-fermion state, but it may also develop from SDW or CDW states. In other cases SDW states appear inside the superconducting state. In spite of intense research efforts, the interrelations between the SC, SDW and CDW states remain unclear. The properties of the ground state of real materials may be altered by adjusting a physical parameter (“tuning”). The parameter, x, may be the external magnetic field, pressure or chemical substitution. In some cases, tuning induces a phase transition at T = 0 K, a quantum critical point QCP (at a critical value xc). At, and near, xc the physical properties of the system are dominated by quantum fluctuation resulting in a new state of matter. For systems close to a magnetic instability one distinguishes two types of QCPs depending on the evolution of the Fermi surface near xc. (i) The Fermi surface undergoes only minor changes, SDW type. (ii) The Fermi surface undergoes large changes due to “Kondo- screening destruction”. By analogy, a system close to a CDW instability may result in a QCP, where quantum fluctuations are associated to charge fluctuations near the onset of the CDW instability (CDW-QCP). We plan to investigate materials, where SDW and or CDW instabilities are likely to occur and are superconducting at low temperatures. The aim of our studies is to map out the features that may be attributed to charge and/or spin fluctuations in a variety of different superconducting materials. Materials of interest will be synthesized in the Laboratory of Prof. K. Conder at PSI and of prof. A. Bianchi at the university of Montreal. Characterization by thermal and transport properties will be performed at PSI. High quality single crystalline samples will be selected for further neutron scattering and µSR measurements.
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