Magnetic Excitations in Iron-based Superconductors

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis Magnetic Excitations in Iron-based Superconductors by : Florian Tim Waßer

Download or read book Magnetic Excitations in Iron-based Superconductors written by Florian Tim Waßer and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Magnetic Excitations in Itinerant Iron-based Superconductors

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ISBN 13 :
Total Pages : 109 pages
Book Rating : 4.:/5 (933 download)

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Book Synopsis Magnetic Excitations in Itinerant Iron-based Superconductors by :

Download or read book Magnetic Excitations in Itinerant Iron-based Superconductors written by and published by . This book was released on 2014 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Magnetic Excitations in the Iron Based Superconductors

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ISBN 13 :
Total Pages : 196 pages
Book Rating : 4.:/5 (826 download)

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Book Synopsis Magnetic Excitations in the Iron Based Superconductors by : Leland Weldon Harriger

Download or read book Magnetic Excitations in the Iron Based Superconductors written by Leland Weldon Harriger and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented within are neutron scattering studies detailing the spin dynamics of BaNi[subscript x]Fe2[subscript x]As2 for x = 0 (parent), 0.04 (underdoped), and 0.1 (optimal) dopings, and FeSe[subscript x]Te1[subscript x] for x = 0 (parent), 0.3 (underdoped), and 0.4 (optimal) dopings. These recently discovered Fe-based superconducting compounds are strikingly similar, in many respects, to the cuprate class of unconventional superconductors and share qualitatively similar phase diagrams consisting of a long range ordered magnetic ground state in the parents which, upon doping, is supplanted in favor of superconductivity. The dopings discussed herein allow us to tune through the phase diagram, beginning with long range ordered parents and ending with optimally doped superconductors with short range magnetic correlations. For BaFe2As2, the excitations in the ordered state are strongly damped and persist up to 300meV. Low energies excitations are centered around Q[subscript AMF] and disperse towards the zone boundary with increasing energy. Only scattering above 100meV is effected when warming above T[subscript N]. In underdoped x = 0.04 BaNi[subscript x]Fe2−[subscript x]As2, we find an order of magnitude reduction in the coupling between layers and a corresponding crossover from 3D to 2D magnetism. In coauthor work on optimal doped x = 0.1 BaNi[subscript x]Fe2−[subscript x]As2 we establish the existence of a 3D resonance mode in the superconducting state. Excitations at optimal doping above the resonance are very similar to the paramagnetic scattering observed in the parent and consists of diffuse scattering below 100meV while above this threshold the signal has similar dispersion, linewidths, and intensity as the ordered state. For FeTe, I discuss our existing efforts and data collection aimed at addressing issues associated with calculating the effective moment from Q, E-integrated data. Tuning through the phase diagram to the x = 0.3 underdoped FeSe[subscript x]Te1−[subscript x] system we find filamentary superconductivity with magnetic spectral weight sitting at both the AFM and nesting vector. Upon reaching x = 0.4 optimal doping, the scattering completely transfers over to the nesting vector and a 2D resonance mode appears below T[subscript c].

Magnetism and Superconductivity in Iron-based Superconductors as Probed by Nuclear Magnetic Resonance

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Publisher : Springer Science & Business Media
ISBN 13 : 3834824232
Total Pages : 183 pages
Book Rating : 4.8/5 (348 download)

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Book Synopsis Magnetism and Superconductivity in Iron-based Superconductors as Probed by Nuclear Magnetic Resonance by : Franziska Hammerath

Download or read book Magnetism and Superconductivity in Iron-based Superconductors as Probed by Nuclear Magnetic Resonance written by Franziska Hammerath and published by Springer Science & Business Media. This book was released on 2012-08-31 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Magnetic Resonance (NMR) has been a fundamental player in the studies of superconducting materials for many decades. This local probe technique allows for the study of the static electronic properties as well as of the low energy excitations of the electrons in the normal and the superconducting state. On that account it has also been widely applied to Fe-based superconductors from the very beginning of their discovery in February 2008. This dissertation comprises some of these very first NMR results, reflecting the unconventional nature of superconductivity and its strong link to magnetism in the investigated compounds LaO1–xFxFeAs and LiFeAs.

Iron-Based Superconductivity

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Publisher : Springer
ISBN 13 : 3319112546
Total Pages : 452 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis Iron-Based Superconductivity by : Peter D. Johnson

Download or read book Iron-Based Superconductivity written by Peter D. Johnson and published by Springer. This book was released on 2015-01-06 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents an in-depth review of experimental and theoretical studies on the newly discovered Fe-based superconductors. Following the Introduction, which places iron-based superconductors in the context of other unconventional superconductors, the book is divided into three sections covering sample growth, experimental characterization, and theoretical understanding. To understand the complex structure-property relationships of these materials, results from a wide range of experimental techniques and theoretical approaches are described that probe the electronic and magnetic properties and offer insight into either itinerant or localized electronic states. The extensive reference lists provide a bridge to further reading. Iron-Based Superconductivity is essential reading for advanced undergraduate and graduate students as well as researchers active in the fields of condensed matter physics and materials science in general, particularly those with an interest in correlated metals, frustrated spin systems, superconductivity, and competing orders.

Iron-based Superconductors

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Publisher : CRC Press
ISBN 13 : 9814303224
Total Pages : 564 pages
Book Rating : 4.8/5 (143 download)

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Book Synopsis Iron-based Superconductors by : Nan Lin Wang

Download or read book Iron-based Superconductors written by Nan Lin Wang and published by CRC Press. This book was released on 2012-11-19 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: From fundamental physics point of view, iron-based superconductors have properties that are more amenable to band structural calculations. This book reviews the progress made in this fascinating field. With contributions from leading experts, the book provides a guide to understanding materials, physical properties, and superconductivity mechanism aspects, and is important for students and beginners to have an overall view of the recent progress in this active field.

Nematicity in iron-based superconductors

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Publisher : Frontiers Media SA
ISBN 13 : 2832514707
Total Pages : 120 pages
Book Rating : 4.8/5 (325 download)

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Book Synopsis Nematicity in iron-based superconductors by : Qisi Wang

Download or read book Nematicity in iron-based superconductors written by Qisi Wang and published by Frontiers Media SA. This book was released on 2023-02-15 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Phase Diagram and Magnetic Excitations of BaFe2-xNixAs2: A Neutron Scattering Study

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Publisher : Springer
ISBN 13 : 981104998X
Total Pages : 127 pages
Book Rating : 4.8/5 (11 download)

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Book Synopsis Phase Diagram and Magnetic Excitations of BaFe2-xNixAs2: A Neutron Scattering Study by : Xingye Lu

Download or read book Phase Diagram and Magnetic Excitations of BaFe2-xNixAs2: A Neutron Scattering Study written by Xingye Lu and published by Springer. This book was released on 2017-07-10 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies the structural, magnetic and electronic properties of, as well as magnetic excitations in, high-temperature BaFe2-xNixAs2 superconductors using neutron diffraction and neutron spectroscopic methods. It describes the precise determination of the phase diagram of BaFe2-xNixAs2, which demonstrates strong magnetoelastic coupling and avoided quantum criticality driven by short-range incommensurate antiferromagnetic order, showing cluster spin glass behavior. It also identifies strong nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2. The nematic correlations have similar temperature and doping dependence as resistivity anisotropy in detwinned samples, which suggests that they are intimately connected. Lastly, it investigates doping evolution of magnetic excitations in overdoped BaFe2-xNixAs2 and discusses the links with superconductivity. This book includes detailed neutron scattering results on BaFe2-xNixAs2 and an introduction to neutron scattering techniques, making it a useful guide for readers pursuing related research.

The Iron Pnictide Superconductors

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Publisher : Springer
ISBN 13 : 3319561170
Total Pages : 197 pages
Book Rating : 4.3/5 (195 download)

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Book Synopsis The Iron Pnictide Superconductors by : Ferdinando Mancini

Download or read book The Iron Pnictide Superconductors written by Ferdinando Mancini and published by Springer. This book was released on 2017-05-25 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers different aspects of the physics of iron-based superconductors ranging from the theoretical, the numerical and computational to the experimental ones. It starts from the basic theory modeling many-body physics in Fe-superconductors and other multi-orbital materials and reaches up to the magnetic and Cooper pair fluctuations and nematic order. Finally, it offers a comprehensive overview of the most recent advancements in the experimental investigations of iron based superconductors.

Theory of Spin-fluctuation Induced Superconductivity in Iron-based Superconductors

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ISBN 13 :
Total Pages : pages
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Book Synopsis Theory of Spin-fluctuation Induced Superconductivity in Iron-based Superconductors by :

Download or read book Theory of Spin-fluctuation Induced Superconductivity in Iron-based Superconductors written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation we focus on the investigation of the pairing mechanism in the recently discovered high-temperature superconductor, iron pnictides. Due to the proximity to magnetic instability of the system, we considered short-range spin fluctuations as the major mediating source to induce superconductivity. Our calculation supports the magnetic fluctuations as a strong candidate that drives Cooper-pair formation in this material. We find the corresponding order parameter to be of the so-called ss-wave type and show its evolution with temperature as well as the capability of supporting high transition temperature up to several tens of Kelvin. On the other hand, our itinerant model calculation shows pronounced spin correlation at the observed antiferromagnetic ordering wave vector, indicating the underlying electronic structure in favor of antiferromagnetic state. Therefore, the electronic degrees of freedom could participate both in the magnetic and in the superconducting properties. Our work shows that the interplay between magnetism and superconductivity plays an important role to the understanding of the rich physics in this material. The magnetic-excitation spectrum carries important information on the nature of magnetism and the characteristics of superconductivity. We analyze the spin excitation spectrum in the normal and superconducting states of iron pnictides in the magnetic scenario. As a consequence of the sign-reversed gap structure obtained in the above, a spin resonance mode appears below the superconducting transition temperature. The calculated resonance energy, scaled with the gap magnitude and the magnetic correlation length, agrees well with the inelastic neutron scattering (INS) measurements. More interestingly, we find a common feature of those short-range spin fluctuations that are capable of inducing a fully gapped ss state is the momentum anisotropy with elongated span along the direction transverse to the antiferromagnetic momentum transfer. This calculated intrinsic anisotropy exists both in the normal and in the superconducting state, which naturally explains the elliptically shaped magnetic responses observed in INS experiments. Our detailed calculation further shows that the magnetic resonance mode exhibits an upward dispersion-relation pattern but anisotropic along the transverse and longitudinal directions. We also perform a qualitative analysis on the relationship between the anisotropic momentum structure of the magnetic fluctuations and the stability of superconducting phase by intraorbital but interband pair scattering to show the consistency of the magnetic mechanism for superconductivity. As discussed for cuprates, an important identification of the mediating boson is from the fermionic spectrum. We study the spectral function in the normal and superconducting state. Not only do we extract the gap magnitude on the electron- and hole-pockets to show the momentum structure of the gap, but also find a peak-dip-hump feature in the electron spectrum, which reflects the feedback from the spin excitations on fermions. This serves as an interpretation of the kink structure observed in ARPES measurements.

Study Magnetic Excitations in Doped Transition Metal Oxides Using Inelastic Neutron Scattering

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (967 download)

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Book Synopsis Study Magnetic Excitations in Doped Transition Metal Oxides Using Inelastic Neutron Scattering by :

Download or read book Study Magnetic Excitations in Doped Transition Metal Oxides Using Inelastic Neutron Scattering written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the interplay between magnetism and superconductivity continues to be a "hot" topic in modern condensed matter physics. The discovery of high-temperature superconductivity in iron-based materials in 2008 provided an unique opportunity to compare and contrast these materials with traditional high-Tc copper oxide superconductors. Neutron scattering plays an important role in determining the dynamical spin properties in these materials. This proposal is a continuation of previous DOE supported proposal. This report summarizes the final progress we have made over from May 2005 till Aug. 2013. Overall, we continue to carry out extensive neutron scattering experiments on Fe-based materials, focusing on understanding their magnetic properties. In addition, we have established a materials laboratory at UT that has allowed us to grow these superconductors. Because neutron scattering typically demands a large amount of samples, by growing these materials in our own laboratory, we can now pursuit neutron scattering experiments over the entire electronic phase diagram, focusing on regions of interests. The material synthesis laboratory at UT was established entirely with the support of DOE funding. This not only allowed us to carry out neutron scattering experiments, but also permit us to provide samples to other US/International collaborators for studying these materials.

Low Energy Quasiparticle Excitations in Cuprates and Iron-based Superconductors

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ISBN 13 :
Total Pages : 153 pages
Book Rating : 4.:/5 (111 download)

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Book Synopsis Low Energy Quasiparticle Excitations in Cuprates and Iron-based Superconductors by : Ken Nakatsukasa

Download or read book Low Energy Quasiparticle Excitations in Cuprates and Iron-based Superconductors written by Ken Nakatsukasa and published by . This book was released on 2018 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microscopic properties of the phonon mediated conventional superconductors are well explained by the Bardeen-Cooper-Schrieer (BCS) theory. However, a comprehensive description of the unconventional superconductivity such as the cuprates and iron-based superconductors is still under considerable debate. One of the theories proposed for explaining the pairing mechanism is the spin fluctuation exchange perhaps playing a leading role in inducing the unconventional superconductivity[1]. These materials are thought to be unconventional because they share certain commonalities that are absent in the conventional superconductors. The materials possess variety of phases upon doping including the superconductivity residing in close proximity to magnetism. They show an anisotropic superconducting order parameter. The transition temperatures tend to be higher than those predicted by the conventional electron-phonon couplings. These observations differ from the conventional superconductors indicating that the electron-phonon interactions may be non-factors or play a minimal role in paring. However, a significant phonon renormalization interpreted from photoemission spectroscopy[2], a pronounced isotope effect in cuprates[3], and the emergence of the replica band due to strong forward scattering phonons[4] raise questions regarding the role of phonons in these magnetic superconductors. McMillan and Rowell have studied the low energy excitations seen from a tunneling experiment to prove the electron-phonon coupling was indeed driving the superconductivity, and thus validated the BCS theory[5]. If the unconventional pairing is explained by the exchange of bosons, then one could use the extended version of the BCS theory such as the Eliashberg theory to describe properties of the superconductivity. In the present analysis, we have investigated the low energy features seen in various unconventional superconductors using a fully self-consistent algorithm. We find that the bosonic excitation picture has correctly explained many experimental features, though there were properties. The present analysis has enlightened the picture that the spin fluctuation exchange plays a pivotal role in mediating the pairing; we may further argue that the phonons can play an important role in renormalizing the electronic structure in cuprates; additionally, the forward scattering phonons can coexist with the spin fluctuation exchange to greatly enhance the transition temperature in a selected layered materials.

Neutron Scattering - Magnetic and Quantum Phenomena

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Publisher : Elsevier
ISBN 13 : 0128020938
Total Pages : 534 pages
Book Rating : 4.1/5 (28 download)

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Book Synopsis Neutron Scattering - Magnetic and Quantum Phenomena by :

Download or read book Neutron Scattering - Magnetic and Quantum Phenomena written by and published by Elsevier. This book was released on 2015-11-29 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron Scattering - Magnetic and Quantum Phenomena provides detailed coverage of the application of neutron scattering in condensed matter research. The book's primary aim is to enable researchers in a particular area to identify the aspects of their work where neutron scattering techniques might contribute, conceive the important experiments to be done, assess what is required to carry them out, write a successful proposal for one of the major user facilities, and perform the experiments under the guidance of the appropriate instrument scientist. An earlier series edited by Kurt Sköld and David L. Price, and published in the 1980s by Academic Press as three volumes in the series Methods of Experimental Physics, was very successful and remained the standard reference in the field for several years. This present work has similar goals, taking into account the advances in experimental techniques over the past quarter-century, for example, neutron reflectivity and spin-echo spectroscopy, and techniques for probing the dynamics of complex materials of technological relevance. This volume complements Price and Fernandez-Alonso (Eds.), Neutron Scattering - Fundamentals published in November 2013. Covers the application of neutron scattering techniques in the study of quantum and magnetic phenomena, including superconductivity, multiferroics, and nanomagnetism Presents up-to-date reviews of recent results, aimed at enabling the reader to identify new opportunities and plan neutron scattering experiments in their own field Provides a good balance between theory and experimental techniques Provides a complement to Price and Fernandez-Alonso (Eds.), Neutron Scattering - Fundamentals published in November 2013

Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors

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Publisher : KIT Scientific Publishing
ISBN 13 : 3731507471
Total Pages : 244 pages
Book Rating : 4.7/5 (315 download)

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Book Synopsis Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors by : Jandke, Jasmin Maria

Download or read book Elastic and Inelastic Scanning Tunneling Spectroscopy on Iron-Based Superconductors written by Jandke, Jasmin Maria and published by KIT Scientific Publishing. This book was released on 2019-05-02 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Handbook of Superconductivity

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Publisher : CRC Press
ISBN 13 : 1000600076
Total Pages : 1088 pages
Book Rating : 4.0/5 (6 download)

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Book Synopsis Handbook of Superconductivity by : David A. Cardwell

Download or read book Handbook of Superconductivity written by David A. Cardwell and published by CRC Press. This book was released on 2022-07-05 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first of three volumes of the extensively revised and updated second edition of the Handbook of Superconductivity. The past twenty years have seen rapid progress in superconducting materials, which exhibit one of the most remarkable physical states of matter ever to be discovered. Superconductivity brings quantum mechanics to the scale of the everyday world where a single, coherent quantum state may extend over a distance of metres, or even kilometres, depending on the size of a coil or length of superconducting wire. Viable applications of superconductors rely fundamentally on an understanding of this intriguing phenomena and the availability of a range of materials with bespoke properties to meet practical needs. This first volume covers the fundamentals of superconductivity and the various classes of superconducting materials, which sets the context and background for Volumes 2 and 3. Key Features: Covers the depth and breadth of the field Includes contributions from leading academics and industry professionals across the world Provides hands-on guidance to the manufacturing and processing technologies A comprehensive reference, this handbook is suitable for both graduate students and practitioners in experimental physics, materials science and multiple engineering disciplines, including electronic and electrical, chemical, mechanical, metallurgy and others.

Dynamics of a Quantum Spin Liquid

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Publisher : Springer
ISBN 13 : 3319239538
Total Pages : 150 pages
Book Rating : 4.3/5 (192 download)

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Book Synopsis Dynamics of a Quantum Spin Liquid by : Johannes Knolle

Download or read book Dynamics of a Quantum Spin Liquid written by Johannes Knolle and published by Springer. This book was released on 2016-04-05 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an exact theoretical study of dynamical correlation functions in different phases of a two-dimensional quantum spin liquid. By calculating the dynamical spin structure factor and the Raman scattering cross section, this thesis shows that there are salient signatures—qualitative and quantitative—of the Majorana fermions and the gauge fluxes emerging as effective degrees of freedom in the exactly solvable Kitaev honeycomb lattice model. The model is a representative of a class of spin liquids with Majorana fermions coupled to Z2 gauge fields. The qualitative features of the response functions should therefore be characteristic for this broad class of topological states.

Non-Universal Superconducting Gap Structure in Iron-Pnictides Revealed by Magnetic Penetration Depth Measurements

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Publisher : Springer Science & Business Media
ISBN 13 : 4431542949
Total Pages : 135 pages
Book Rating : 4.4/5 (315 download)

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Book Synopsis Non-Universal Superconducting Gap Structure in Iron-Pnictides Revealed by Magnetic Penetration Depth Measurements by : Kenichiro Hashimoto

Download or read book Non-Universal Superconducting Gap Structure in Iron-Pnictides Revealed by Magnetic Penetration Depth Measurements written by Kenichiro Hashimoto and published by Springer Science & Business Media. This book was released on 2013-02-12 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book the author presents two important findings revealed by high-precision magnetic penetration depth measurements in iron-based superconductors which exhibit high-transition temperature superconductivity up to 55 K: one is the fact that the superconducting gap structure in iron-based superconductors depends on a detailed electronic structure of individual materials, and the other is the first strong evidence for the presence of a quantum critical point (QCP) beneath the superconducting dome of iron-based superconductors. The magnetic penetration depth is a powerful probe to elucidate the superconducting gap structure which is intimately related to the pairing mechanism of superconductivity. The author discusses the possible gap structure of individual iron-based superconductors by comparing the gap structure obtained from the penetration depth measurements with theoretical predictions, indicating that the non-universal superconducting gap structure in iron-pnictides can be interpreted in the framework of A1g symmetry. This result imposes a strong constraint on the pairing mechanism of iron-based superconductors. The author also shows clear evidence for the quantum criticality inside the superconducting dome from the absolute zero-temperature penetration depth measurements as a function of chemical composition. A sharp peak of the penetration depth at a certain composition demonstrates pronounced quantum fluctuations associated with the QCP, which separates two distinct superconducting phases. This gives the first convincing signature of a second-order quantum phase transition deep inside the superconducting dome, which may address a key question on the general phase diagram of unconventional superconductivity in the vicinity of a QCP.