Author: Nikola Anna EgetenmeyerPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Interplay Between Superconductivity and Magnetism
Author: Nikola Anna EgetenmeyerElectrons in Solids
Author: Richard A DunlapPublisher: Morgan & Claypool Publishers
ISBN: 1643276905
Category : Science
Languages : en
Pages : 114
Book Description
The transport of electric charge through most materials is well described in terms of their electronic band structure. The present book deals with two cases where the charge transport in a solid is not described by the simple band structure picture of the solid. These cases are related to the phenomena of the quantum Hall effect and superconductivity. Part I of this book deals with the quantum Hall effect, which is a consequence of the behavior of electrons in solids when they are constrained to move in two dimensions. Part II of the present volume describes the behavior of superconductors, where electrons are bound together in Cooper pairs and travel through a material without resistance.
Interplay Between Superconductivity and Magnetism in Iron-based Superconductors
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This proposal is for theoretical work on strongly correlated electron systems, which are at the center of experimental and theoretical activities in condensed-matter physics. The interest to this field is driven fascinating variety of observed effects, universality of underlying theoretical ideas, and practical applications. I propose to do research on Iron-based superconductors (FeSCs), which currently attract high attention in the physics community. My goal is to understand superconductivity and magnetism in these materials at various dopings, the interplay between the two, and the physics in the phase in which magnetism and superconductivity co-exist. A related goal is to understand the origin of the observed pseudogap-like behavior in the normal state. My research explores the idea that superconductivity is of electronic origin and is caused by the exchange of spin-fluctuations, enhanced due to close proximity to antiferromagnetism. The multi-orbital/multi-band nature of FeSCs opens routes for qualitatively new superconducting states, particularly the ones which break time-reversal symmetry. By all accounts, the coupling in pnictdes is below the threshold for Mott physics and I intend to analyze these systems within the itinerant approach. My plan is to do research in two stages. I first plan to address several problems within weak-coupling approach. Among them: (i) what sets stripe magnetic order at small doping, (ii) is there a preemptive instability into a spin-nematic state, and how stripe order affects fermions; (iii) is there a co-existence between magnetism and superconductivity and what are the system properties in the co-existence state; (iv) how superconductivity emerges despite strong Coulomb repulsion and can the gap be s-wave but with nodes along electron FSs, (v) are there complex superconducting states, like s+id, which break time reversal symmetry. My second goal is to go beyond weak coupling and derive spin-mediated, dynamic interaction between fermions, understand what sets the upper scale for attractive interaction, compute T_c, and then obtain and solve matrix non-linear gap equation for spin-mediated pairing and study various feedbacks from the pairing on fermions on ARPES spectra, optical and thermal conductivity, and other observables, The problems I have chosen are quite generic, and the understanding of magnetically-mediated superconductivity in the strong-coupling regime will not only advance the theory of superconductivity in FeSCs, but will contribute to a generic understanding of the pairing of fermions near quantum-critical points -- the problems ranging from s-wave pairing by soft optical phonons to to color superconductivity of quarks mediated by a gluon exchange.
Interplay Between Magnetism and Superconductivity in the Cuprates
Author: Amit KanigelOn the Interplay of Superconductivity and Magnetism
Author: Benjamin James PowellInterplay Between Magnetism and Superconductivity in High-temperature Superconductors La(2-x)Ba(x)CuO(4) and Fe(1+y)Te(1-x)Se(x)
Author: Jinsheng WenPublisher:
ISBN:
Category : Materials science
Languages : en
Pages :
Book Description
Interplay Between Magnetism and Superconductivity in Iron Based High Temperature Superconductors
Author: Stephen PricePublisher:
ISBN: 9783893369218
Category :
Languages : en
Pages : 196
Book Description
Interplay Between Superconductivity and Itinerant Ferromagnetism in Y9Co-- at High Pressure
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The theory of the interplay between superconductivity and itinerant ferromagnetism based on the single conduction band model in the mean field approximation is summarized. This theory predicts that superconductivity and itinerant ferromagnetism cannot co-exist, that the higher temperature magnetic phase can transform into the low temperature superconducting state, and that a superconducting state will not transform into a ferromagnetic state at a temperature below the superconducting transition. For the magnetic superconductor Y9Co-- we have reviewed the experimental results and in particular, we have shown that pressure suppresses magnetism resulting in a higher superconducting transition temperature and have concluded that Y9Co-- is an itinerant magnet. Pressure also sharpens the superconducting transition and increases the upper critical field, signifying that the ferromagnetic correlations and superconducting fluctuations co-exist but very spatially. For pressures greater than 6 kbar, the magnetoresistance is always positive, further indicating the suppression of magnetism by high pressure. Several microscopic experiments and some improvement in theory are suggested.
Interplay of Magnetism and Superconductivity in Strongly Correlated Electron Systems
Author: Daniel PodolskyPublisher:
ISBN:
Category : Antiferromagnetism
Languages : en
Pages : 392
Book Description
The Interplay Between Magnetism and Superconductivity in Strongly Correlated Materials
Author: Tao HuPublisher:
ISBN:
Category : Magnetism
Languages : en
Pages : 102
Book Description
We performed out-of-plane angular dependent magnetoresistivity measurements on La0.7Ca0.3MnO3/YBa2Cu3O7-[delta](LCMO/YBCO) trilayer heterostructure. Our results show that the conductance of the LCMO layers of the trilayer increases by two orders of magnitude below the superconducting transition temperature Tc of the trilayer. We found that triplet correlations are induced in LCMO over an effective penetration depth [xi]F resulting in this significant increase in conductance. We estimated the dissipation present in the LCMO layers is [xi]F~=4.7nm at 10 K. We concluded that triplet superconducting pairs are induced in the LCMO layers. In-plane resistance and magnetization measurements were performed on LCMO/YBCO trilayers below the Tc of the YBCO layer. We found two magnetoresistance (MR) peaks. The first MR peak is consistent with the suppression of superconductivity due to the stray fields generated by the domain walls and the second one is most likely the result of the antiparallel orientation of the net magnetic moment of the top and bottom LCMO layers. We concluded that stray field and spin imbalance effects coexist and compete, hence modulate the superconductivity of heterostructures. We performed in-plane angular dependent resistivity measurements in the non-Fermi liquid regime of CeCoIn5 single crystals. We found the presence of two different scaling behaviors in the low-field region where resistivity shows a linear temperature dependence, separated by a critical angle related with the anisotropy of CeCoIn5 . We explained this anomalous angular dependent resistivity in terms of d-wave density waves with Landau quantization of the quasiparticle spectrum. Current-voltage (I-V) measurements were performed on CeCoIn5 in the mixed state. We observed that the flux-flow resistivity [rho]ff obtained from I-V measurements is abnormal. Specifically, [rho]ff increases sharply with decreasing magnetic field and temperature. Our result revealed the abnormal insulating core of the vortex line structure. We found that vortex core becomes normal when the system is tuned away from quantum critical point. We concluded that the abnormal insulating core is a result of quantum criticality.