Antiferromagnetism and Superconductivity in Ce-based Heavy-Fermion Systems

Antiferromagnetism and Superconductivity in Ce-based Heavy-Fermion Systems PDF Author: Edit Lengyel
Publisher: Cuvillier Verlag
ISBN: 386727696X
Category :
Languages : en
Pages : 213

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Antiferromagnetism and Superconductivity in Ce-based Heavy-Fermion Systems

Antiferromagnetism and Superconductivity in Ce-based Heavy-Fermion Systems PDF Author: Edit Lengyel
Publisher: Cuvillier Verlag
ISBN: 386727696X
Category :
Languages : en
Pages : 213

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Magnetism in Heavy Fermion Systems

Magnetism in Heavy Fermion Systems PDF Author: Harry Brian Radousky
Publisher: World Scientific
ISBN: 9789812792655
Category : Science
Languages : en
Pages : 398

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Book Description
Magnetism in Heavy Fermion Systems is a review volume which covers an important subset of topics in the field of heavy fermion and non-Fermi liquid physics. It summarizes much of the experimental information in these areas, and includes an article which discusses theoretical interpretations of the complex magnetic behavior of heavy fermion systems. The topics covered include heavy fermion superconductivity, muon spin relaxation in small-moment heavy fermions, neutron scattering from heavy fermions, random localized magnetism in heavy fermions, and magnetism in Pr-containing cuprates. One feature of the book which should be helpful to graduate students and new workers in the field is the extensive references and a separate list of review articles.

Superconductivity, Magnetism, Quantum Criticality, And Hidden Order In Quantum Materials

Superconductivity, Magnetism, Quantum Criticality, And Hidden Order In Quantum Materials PDF Author: Dom Lal Kunwar
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The heavy fermions (HF) are strongly correlated electron systems consisting of intermetallic compounds of lanthanides and actinides ions with f -electrons unfilled shells. These systems are very rich in physics and the interplay between competing interactions results in various interesting physical phenomena such as heavy fermion behavior, unconventional superconductivity, non-Fermi-liquid behavior, coexistence of superconductivity and magnetism, and quantum criticality. The origin of such phenomena comes from the interaction of itinerant conduction states with the partially filled 4f - or 5f -electron states of rare earth elements. The study of such important physical phenomena can be possible by tuning the system using nonthermal control parameters, such as chemical composition, magnetic field, and applied pressure. So, studying the chemical pressure effect on heavy fermion systems with or without magnetic field is an intriguing idea to construct various phase diagrams and study their phase transitions. We performed heat capacity (HC), magnetoresistance (MR), and resistivity measurements on the Ce-based 115 and U-based 122 heavy fermion materials at low temperatures. We studied the nature of the quantum critical point, second-order phase transition, and the possible interplay between superconductivity and magnetism. First, we were motivated by the possibility of observing the coexistence of magnetism and unconventional superconductivity in the heavy fermion Ce1-xSmxCoIn5 alloys. We performed specific heat, MR, and resistivity measurements in different magnetic fields. We investigated how the samarium substitution on the cerium site affects the magnetic-field-tuned quantum criticality of stoichiometric CeCoIn5. We have observed Fermi-liquid to non-Fermi-liquid crossovers in the temperature dependence of the electronic specific heat and resistivity at higher external magnetic fields. We obtained the magnetic-field-induced quantum critical point (HQCP) by extrapolating the crossover temperature to zero temperature. Furthermore, we performed a scaling analysis of the electronic specific heat and confirmed the existence of the QCP. According to our findings, the magnitude of (HQCP) decreases as the samarium content rises and ultimately becomes zero. The electronic specific heat and resistivity data reveal a zero-field QCP for xcr = 0.15, which falls inside the antiferromagnetic and superconducting coexistence region. Next, we performed measurements of the heat capacity as a function of temperature in a single crystals URu2-xOsxSi2. Our experimental results show that the critical temperature of the second-order phase transition increases while the value of the Sommerfeld coefficient in the ordered state decreases with an increase in osmium concentration. We also observed the increase in the magnitude of the heat capacity at the critical temperature and a broadening of the critical fluctuations region with an increase in Os concentration. We analyze the experimental data using the Haule- Kotliar model, which identifies the 'hidden order' transition in the parent material URu2Si2 as a transition to a state with nonzero hexadecapolar moment. We showed that our experimental results are consistent with this model. In conclusion, we studied the interplay between superconductivity and magnetism in Ce based 115 and U based 122 single crystal alloys using heat capacity, magnetoresistivity, and resistivity measurements in both cryogenic systems including He-4 and He-3. The understating of various phenomena in these heavy fermions could be helpful in developing higher transition temperature superconductors, energy storage devices, quantum computers, and memory devices in the future.

Physics Of Heavy Fermions: Heavy Fermions And Strongly Correlated Electrons Systems

Physics Of Heavy Fermions: Heavy Fermions And Strongly Correlated Electrons Systems PDF Author: Yoshichika Onuki
Publisher: World Scientific
ISBN: 9813232218
Category : Science
Languages : en
Pages : 336

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Book Description
A large variety of materials prove to be fascinating in solid state and condensed matter physics. New materials create new physics, which is spearheaded by the international experimental expert, Prof Yoshichika Onuki. Among them, the f electrons of rare earth and actinide compounds typically exhibit a variety of characteristic properties, including spin and charge orderings, spin and valence fluctuations, heavy fermions, and anisotropic superconductivity. These are mainly manifestations of better competitive phenomena between the RKKY interaction and the Kondo effect. The present text is written so as to understand these phenomena and the research they prompt. For example, superconductivity was once regarded as one of the more well-understood many-body problems. However, it is, in fact, still an exciting phenomenon in new materials. Additionally, magnetism and superconductivity interplay strongly in heavy fermion superconductors. The understanding of anisotropic superconductivity and magnetism is a challenging problem in solid state and condensed matter physics. This book will tackle all these topics and more.

Proceedings of the Yamada Conference XVIII on Superconductivity in Highly Correlated Fermion Systems

Proceedings of the Yamada Conference XVIII on Superconductivity in Highly Correlated Fermion Systems PDF Author: M. Tachiki
Publisher: Elsevier
ISBN: 1483275175
Category : Science
Languages : en
Pages : 561

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Book Description
Superconductivity in Highly Correlated Fermion Systems documents the proceedings of the Yamada Conference XVIII on Superconductivity in Highly Correlated Fermion Systems held in Sendai, Japan, from August 31 to September 3, 1987. This book compiles selected papers on the experimental and theoretical advances in the study of superconductivity. The topics include the superconductivity and magnetism in heavy-electron materials, magneto-resistance of heavy-fermion compounds, and magnetic fluctuations and order in exotic superconductors. The fabrication and properties of thin superconducting oxide films, bipolaron models of superconductors, superconducting properties of superlattices, and flux quantization on quasi-crystalline networks are also covered. This publication is recommended for physicists and students researching on the superconductivity in highly correlated fermion systems.

Quantum Critical Phenomena of Valence Transition

Quantum Critical Phenomena of Valence Transition PDF Author: Shinji Watanabe
Publisher: Springer Nature
ISBN: 9819935180
Category : Science
Languages : en
Pages : 220

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Book Description
This book comprehensively presents an unconventional quantum criticality caused by valence fluctuations, which offers theoretical understanding of unconventional Fermi-liquid properties in cerium- and ytterbium-based heavy fermion metals including CeCu2(Si,Ge)2 and CeRhIn5 under pressure, and quasicrystal β-YbAlB4 and Yb15Al34Au51. The book begins with an introduction to fundamental concepts for heavy fermion systems, valence fluctuation, and quantum phase transition, including self-consistent renormalization group theory. A subsequent chapter is devoted to a comprehensive description of the theory of the unconventional quantum criticality based on a valence transition, featuring explicit temperature dependence of various physical quantities, which allows for comparisons to relevant experiments. Lastly, it discusses how ubiquitous the valence fluctuation is, presenting candidate materials not only in heavy fermions, but also in strongly correlated electrons represented by high-Tc superconductor cuprates. Introductory chapters provide useful materials for learning fundamentals of heavy fermion systems and their theory. Further, experimental topics relevant to valence fluctuations are valuable resources for those who are new to the field to easily catch up with experimental background and facts.

Theoretical and Experimental Aspects of Valence Fluctuations and Heavy Fermions

Theoretical and Experimental Aspects of Valence Fluctuations and Heavy Fermions PDF Author: L.C. Gupta
Publisher: Springer Science & Business Media
ISBN: 1461309476
Category : Science
Languages : en
Pages : 749

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Book Description
During the Koln meeting (August 28-31, 1984), Irdia was chosen as the venue for the next International Conference on Valence Fluctuations. lhis was in recognition ard appreciation of the work done, both experimental ard theoretical, by the Irdian scientists in this area during the last decade. We decided to hold this Conference in the month of January, 1987 at Bangalore. lhe subject of Valence Fluctuations has kept itself alive ard active as it has provided many shocks ard suprises particularly among the Ce- ard U-based intermetallies. lhe richness of many interesting physical phenomena occurring in mixed valent materials, the flexibility of modifying their physical properties (by alloying, for example) ard the possibility of synthesizing a wide variety of new such materials seem to be the key factors in this regard. Barely six months before this Conference, an International Conference on Anomalous Rare Earths and Actinides (ICAREA) had been held at Grenoble (July, 1986) which also focussed on mixed valence ard heavy fermion phenomena. In spite of this, the response to this' Conference was very enthusiastic and encouraging. Many interesting ard important results were presented at this Conference which have been included in this volume.

Investigating Strong Correlated Electron Behavior in Heavy Fermion Cesium Platinum Indium and AFM Insulator Lanthanum Nickel Oxide

Investigating Strong Correlated Electron Behavior in Heavy Fermion Cesium Platinum Indium and AFM Insulator Lanthanum Nickel Oxide PDF Author: Nicholas R. ApRoberts-Warren
Publisher:
ISBN: 9781303442032
Category :
Languages : en
Pages :

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Book Description
The field of strongly correlated electron research is a vibrant and expanding one, with a rich variety of unusual electronic and magnetic behavior. In this thesis we examine two such materials: the heavy fermion superconductor CePt2In7 and anti-ferromagnetic insulator La4Ni3O8. Several years ago, the tetragonal CeMIn5 (M = Co, Rh, Ir) class of heavy fermion systems was discovered, which has revealed a wealth of information concerning the detailed interplay between antiferromagnetism and superconductivity. The basic structural elements of these materials are Ce-In planes, which give rise to a two-dimensional character to the electronic behavior. CePt2In7 is the another member of this heavy fermion class with a very large crystal anisotropy. Our nuclear magnetic resonance (NMR) measurements, which focused on the 115In nucleus, reveal that this system is antiferromagnetic below T[N] = 5.2 K, with staggered antiferromagnetic ordering in-plane, and collinear antiferromagnetic correlations between adjacent planes. We also report measurements of the spin-lattice relaxation rate (T1) both at ambient and under isotropic pressure. We additionally examined the 195Pt signal and used its Knight Shift to extract the Kondo liquid and local moment components of the magnetic susceptbility. These components are then analyzed within the context of the ``two-fluid" model of mixed Kondo/local moment systems. Though there are metal-oxide superconductors utilizing many different transition elements, there have been no nickel-oxide superconductors as of yet. The desire to investigate this paucity of superconductivity leads us to La4Ni3O8, which has many structural and electronic similarities to the high-T[c] cuprates. This compound, produced via oxygen-depletion from a parent compound, contains two-dimensional layers of NiO2 with unusual Ni valences. We report 139La NMR data in La4Ni3O8 that confirm previously reported antiferromagnetic order below T[N] ~ 105 K. Our data reveal dramatic changes in resonance lineshapes, and T1 measurements evidence of low-temperature antiferromagnetic fluctuations associated with the onset of long-range order below T[N], even though there is evidence of a Fermi surface below T[N].

Strongly Correlated Systems

Strongly Correlated Systems PDF Author: Adolfo Avella
Publisher: Springer
ISBN: 3662441330
Category : Science
Languages : en
Pages : 329

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Book Description
The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for any other researcher in the field who appreciates consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possible way, with the working details of a specific technique.

ELECTRON-PHONON INTERACTION AND ITS EFFECTS IN HEAVY FERMION SYSTEMS

ELECTRON-PHONON INTERACTION AND ITS EFFECTS IN HEAVY FERMION SYSTEMS PDF Author: Dr. Jitendra Sahoo
Publisher: Newredmars Education Pvt Ltd
ISBN: 9393620075
Category : Art
Languages : en
Pages : 101

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Book Description
The story of heavy fermions (HF) begun with the discovery of the low temperature behaviour of CeAl3 by Andres et al. in the year 1975 took the momentum after the discovery of superconductivity in CeCu2Si2 by Steglich et al. in the year 1979 . Though HF behaviour is common in the rare-earth elements like Ce, Yb and actinides like U, it is also found to exist in some of the praseodymium (Pr), samarium (Sm) , plutonium (Pu) and more recently in neptunium (Np) systems. These compounds are characterized by the presence of partially filled f-electron bands. At high temperatures, these magnetic moments manifest themselves as a weakly interacting set of local moments of the f electrons with Curie-Weiss susceptibility that coexists with light s or d conduction electrons. But at low temperature, these f-electrons hybridize with conduction electrons near Fermi level via Kondo spin fluctuation which happens through constant exchange spin-flip transition of f-electrons and band electrons in the vicinity of Fermi level. This process leads to a strong mixing of Fermi electrons with the localized f-electrons which is manifested in a renormalization of the Fermi surface and a drastic enhancement of the effective mass of the electrons at Fermi level. Further, in HF systems, electron-phonon interaction (EPI) contributes a lot in manifestation of some of the anomalous behaviour relating to elastic constant, ultrasonic attenuation & sound velocity, anisotropic Fermi surface, Kondo volume collapse etc. In this PhD thesis book in title “Electron phonon interaction and its effect in heavy fermion (HF) systems” the author tries to put some light into the behavoiour of Electron-phonon interaction in describing some of the properties of HF systems at low temperatures. In this 1 st edition, the book has been presented in multicolour edition with profuse colour illustrations so as to increase its clarity, understand ability and legibility, especially of the figures depicted to explain the low temperature behaviour of HF systems. It is hoped that the present book will serve its purpose in attracting young researchers to the field of HF systems. It is my foremost duty to express my deep sense of gratitute to my supervisor Dr. Pratibindhya Nayak , Professor Emeritus, School of Physics, Sambalpur University, Odisha, for his able guidance at every stage of this work.. His innovative methods and inspirational guidance have largely contributed to the conceptualization of the form and content of this book. I am indebted to my family members for their constant support. I am sincerely thankful to the publisher, Newredmars Education to bring my works into light in form of a book Healthy criticism and suggestions for further improvement of the book are solicited.