- The physics of epigenetics

Author(s): Ruggero Cortini, Maria Barbi, Bertrand R. Caré, Christophe Lavelle, Annick Lesne, Julien Mozziconacci, and Jean-Marc VictorEpigenetics is essential in understanding the development, from a … - Colloquium: Non-Markovian dynamics in open quantum systems

Author(s): Heinz-Peter Breuer, Elsi-Mari Laine, Jyrki Piilo, and Bassano VacchiniAn ongoing theme in quantum physics is the interaction of small quantum systems with an environment. If that environmen … - Colloquium: Measuring the neutron star equation of state using x-ray timing

Author(s): Anna L. Watts, Nils Andersson, Deepto Chakrabarty, Marco Feroci, Kai Hebeler, Gianluca Israel, Frederick K. Lamb, M. Coleman Miller, Sharon Morsink, Feryal Özel, Alessandro Patruno, Juri Po … - Phase diagram of QCD in a magnetic field

Author(s): Jens O. Andersen, William R. Naylor, and Anders TranbergThis review addresses the current theoretical understanding of hadronic matter at large magnetic fields. Applications include heavy-i … - Physics of Alfvén waves and energetic particles in burning plasmas

Author(s): Liu Chen and Fulvio ZoncaIn magnetic fusion reactors relying on the burning of deuterium and tritium, sufficient confinement of the alpha particles produced in the nuclear reactions is cruc … - The physics of x-ray free-electron lasers

Author(s): C. Pellegrini, A. Marinelli, and S. ReicheThe advent of x-ray free electron lasers has made possible the study of matter at the characteristic space and time scales of atomic and molecular … - Linac Coherent Light Source: The first five years

Author(s): Christoph Bostedt, Sébastien Boutet, David M. Fritz, Zhirong Huang, Hae Ja Lee, Henrik T. Lemke, Aymeric Robert, William F. Schlotter, Joshua J. Turner, and Garth J. WilliamsIn the five yea … - Delayed-choice gedanken experiments and their realizations

Author(s): Xiao-song Ma, Johannes Kofler, and Anton ZeilingerWave-particle duality lies at the root of quantum mechanics and is central in the description of interferences observed with elementary obj … - Big bang nucleosynthesis: Present status

Author(s): Richard H. Cyburt, Brian D. Fields, Keith A. Olive, and Tsung-Han YehHow do we understand the production of the lightest nuclides from H to Li during the first seconds of cosmic time? This … - Colloquium: Water’s controversial glass transitions

Author(s): Katrin Amann-Winkel, Roland Böhmer, Franz Fujara, Catalin Gainaru, Burkhard Geil, and Thomas LoertingBesides being fundamental for life on Earth, water is one of the complex materials in na … - Experimental tests of particle flow calorimetry

Author(s): Felix Sefkow, Andy White, Kiyotomo Kawagoe, Roman Pöschl, and José RepondMethods of measuring the energies of jets have relied on detection of photons, charged hadrons, and neutral hadrons … - Jerusalem lectures on black holes and quantum information

Author(s): D. HarlowThe quantum mechanics of black holes, and particularly the information paradox, have been a crucial arena for testing theories of quantum gravity. This review covers the quantum ph … - Colloquium: Nanoplasmas generated by intense radiation

Author(s): Kostya (Ken) Ostrikov, Farhat Beg, and Andrew NgPhysical phenomena at the nanoscale can be considerably different from the behavior in the macroscopic world. This rule is also true for plas … - Lattice tests of beyond standard model dynamics

Author(s): Thomas DeGrandOriginally developed for quantum chromodynamics at strong coupling, lattice approximations provide an essential tool applicable to any strongly coupled gauge theory. The resol … - Symmetry violations in nuclear and neutron β decay

Author(s): K. K. Vos, H. W. Wilschut, and R. G. E. TimmermansExperimental searches for new physics beyond the standard model of particle physics are not constrained to the high energy sector alone. Th … - Ion-trap measurements of electric-field noise near surfaces

Author(s): M. Brownnutt, M. Kumph, P. Rabl, and R. BlattHow can the electric noise in the vicinity of a metallic body be measured and understood? Trapped ions, known as unique tools for metrology and … - Cavity-based quantum networks with single atoms and optical photons

Author(s): Andreas Reiserer and Gerhard RempeA vision has formed in recent years of the components necessary for a large-scale quantum network. Single trapped atoms can serve as the nodes of this netw … - Spinodal nanodecomposition in semiconductors doped with transition metals

Author(s): T. Dietl, K. Sato, T. Fukushima, A. Bonanni, M. Jamet, A. Barski, S. Kuroda, M. Tanaka, Pham Nam Hai, and H. Katayama-YoshidaThe occurrence of high-temperature ferromagnetism in transition … - Google matrix analysis of directed networks

Author(s): Leonardo Ermann, Klaus M. Frahm, and Dima L. ShepelyanskyHow can information from communication and social networks in modern societies be processed, classified, and retrieved? For this new … - Spin Hall effects

Author(s): Jairo Sinova, Sergio O. Valenzuela, J. Wunderlich, C. H. Back, and T. JungwirthIn solid-state materials with strong relativistic spin-orbit coupling, charge currents generate transverse spi … - Nobel Lecture: Single molecules, cells, and super-resolution optics

Author(s): Eric BetzigThe 2014 Nobel Prize for Chemistry was shared by Eric Betzig, Stefen W. Hell, and William E. Moerner. These papers are the text of the address given in conjunction with the award … - Nobel Lecture: Nanoscopy with freely propagating light

Author(s): Stefan W. HellThe 2014 Nobel Prize for Chemistry was shared by Eric Betzig, Stefen W. Hell, and William E. Moerner. These papers are the text of the address given in conjunction with the aw … - Nobel Lecture: Single-molecule spectroscopy, imaging, and photocontrol: Foundations for super-resolution microscopy

Author(s): W. E. (William E.) MoernerThe 2014 Nobel Prize for Chemistry was shared by Eric Betzig, Stefen W. Hell, and William E. Moerner. These papers are the text of the address given in conjunction … - Nobel Lecture: Fascinated journeys into blue light

Author(s): Isamu Akasaki[Rev. Mod. Phys. 87, 1119] Published Mon Oct 05, 2015 - Nobel Lecture: Growth of GaN on sapphire via low-temperature deposited buffer layer and realization of p-type GaN by Mg doping followed by low-energy electron beam irradiation

Author(s): Hiroshi AmanoThis is a personal history of one of the Japanese researchers engaged in developing a method for growing GaN on a sapphire substrate, paving the way for the realization of smar … - Nobel Lecture: Background story of the invention of efficient blue InGaN light emitting diodes

Author(s): Shuji Nakamura[Rev. Mod. Phys. 87, 1139] Published Mon Oct 05, 2015 - Quantum Monte Carlo methods for nuclear physics

Author(s): J. Carlson, S. Gandolfi, F. Pederiva, Steven C. Pieper, R. Schiavilla, K. E. Schmidt, and R. B. WiringaQuantum Monte Carlo techniques aim at providing a description of complex quantum syste … - Random-matrix theory of Majorana fermions and topological superconductors

Author(s): C. W. J. BeenakkerRandom-matrix theory has a long history of applications, from nuclear physics to electron localization to quantum dots. This review discusses yet another application of th … - Epidemic processes in complex networks

Author(s): Romualdo Pastor-Satorras, Claudio Castellano, Piet Van Mieghem, and Alessandro VespignaniComplex networks arise in a wide range of biological and sociotechnical systems. Epidemic spreading … - Surface nanobubbles and nanodroplets

Author(s): Detlef Lohse and Xuehua Zhang (张雪花)Surface nanobubbles are nanoscopic gaseous domains on immersed substrates which can survive for days. They were first speculated to exist about 20 years a … - Density functional theory: Its origins, rise to prominence, and future

Author(s): R. O. JonesDensity functional theory has been spectacularly successful in physics, chemistry, and related fields, and it keeps finding new applications. This paper gives an overview of the … - Antiferromagnetic order and spin dynamics in iron-based superconductors

Author(s): Pengcheng DaiIn contrast to conventional BCS superconductors, the observation that superconductivity in unconventional high-temperature materials appears in close proximity to a static anti … - Anderson’s considerations on the flow of superfluid helium: Some offshoots

Author(s): Eric VaroquauxThe aim of this review, based on Anderson’s ideas on phase slippage in superfluid helium, is to convey a physical meaning to the superfluid order parameter and its phase. This … - Attosecond chronoscopy of photoemission

Author(s): Renate Pazourek, Stefan Nagele, and Joachim BurgdörferRecent advances in ultrafast laser spectroscopy have made it possible to study the electron dynamics for physical and chemical processe … - Quantum transport in carbon nanotubes

Author(s): Edward A. Laird, Ferdinand Kuemmeth, Gary A. Steele, Kasper Grove-Rasmussen, Jesper Nygård, Karsten Flensberg, and Leo P. KouwenhovenCarbon nanotubes with multifunctional capabilities are p … - Optical atomic clocks

Author(s): Andrew D. Ludlow, Martin M. Boyd, Jun Ye, E. Peik, and P. O. SchmidtSince 1967 the primary time standard is the cesium atomic clock, based on a hyperfine transition in the microwave domain. … - Macroscopic fluctuation theory

Author(s): Lorenzo Bertini, Alberto De Sole, Davide Gabrielli, Giovanni Jona-Lasinio, and Claudio LandimThe statistical mechanics of systems out of equilibrium provides a formidable challenge. This re … - Neutrino electromagnetic interactions: A window to new physics

Author(s): Carlo Giunti and Alexander StudenikinWith the observation of neutrino masses and mixings, the study of their electromagnetic interactions has assumed greater relevance both as verification … - Lévy walks

Author(s): V. Zaburdaev, S. Denisov, and J. KlafterLévy walks are random walks in which the distribution of step length does not decay exponentially and the velocity of the moving particle is finite. … - Colloquium: Theory of intertwined orders in high temperature superconductors

Author(s): Eduardo Fradkin, Steven A. Kivelson, and John M. TranquadaUnderstanding high temperature superconductors is a central problem in condensed matter physics. Many experiments have uncovered or … - Asymmetries in top quark pair production at hadron colliders

Author(s): J. A. Aguilar-Saavedra, D. Amidei, A. Juste, and M. Pérez-VictoriaSeveral years ago measurements at the Fermilab Tevatron proton-antiproton collider showed top quarks to be produced prefera … - Colloquium: Geometry and optimal packing of twisted columns and filaments

Author(s): Gregory M. GrasonThis Colloquium presents recent progress in understanding constraints and consequences of close-packing geometry of filamentous or columnar materials possessing nontrivial … - Interfacing single photons and single quantum dots with photonic nanostructures

Author(s): Peter Lodahl, Sahand Mahmoodian, and Søren StobbeQuantum dots embedded in photonics nanostructures provide unprecedented control over the interaction between light and matter. This review g … - Quantum error correction for quantum memories

Author(s): Barbara M. TerhalIt may seem inevitable that highly entangled quantum states are susceptible to disturbance through interaction with a decohering environment. However, certain multiqubit en … - Plasma and trap-based techniques for science with positrons

Author(s): J. R. Danielson, D. H. E. Dubin, R. G. Greaves, and C. M. SurkoIn recent years, there has been a wealth of new science involving low-energy antimatter (i.e., positrons and antiprotons) at e … - Baryon resonances in large N_{c} QCD

Author(s): N. Matagne and Fl. StancuThe current status and open challenges of large N_{c} QCD baryon spectroscopy are reviewed. After introducing the 1/N_{c} expansion method, the latest achievements … - Colloquium: Random first order transition theory concepts in biology and physics

Author(s): T. R. Kirkpatrick and D. ThirumalaiThe routine transformation of a liquid, as it is rapidly cooled, resulting in glass formation, is remarkably complex. A theoretical explanation of the dyn … - Colloquium: Time-reversal violation with quantum-entangled B mesons

Author(s): J. Bernabéu and F. Martínez-VidalSymmetry transformations have been proven a bedrock tool for understanding the nature of particle interactions, formulating, and testing fundamental theorie … - Colloquium: Majorana fermions in nuclear, particle, and solid-state physics

Author(s): Steven R. Elliott and Marcel FranzEttore Majorana (1906–1938) disappeared while traveling by ship from Palermo to Naples in 1938. His fate has never been fully resolved and several articles … - Colloquium: 100 years of mass spectrometry: Perspectives and future trends

Author(s): Simon Maher, Fred P. M. Jjunju, and Stephen TaylorMass spectrometry (MS) is widely regarded as the most sensitive and specific general purpose analytical technique. More than a century has … - Dielectric microcavities: Model systems for wave chaos and non-Hermitian physics

Author(s): Hui Cao and Jan WiersigThis is a review on theoretical and experimental studies on dielectric microcavities, which play a significant role in fundamental and applied research. The basic con … - Compass models: Theory and physical motivations

Author(s): Zohar Nussinov and Jeroen van den BrinkCompass models are theories of matter in which the couplings between the internal spin (or other relevant field) components are inherently spatially ( … - Erratum: Bose-Einstein condensation in quantum magnets [Rev. Mod. Phys. 86, 563 (2014)]

Author(s): Vivien Zapf, Marcelo Jaime, and C. D. Batista[Rev. Mod. Phys. 86, 1453] Published Wed Dec 31, 2014 - Cavity optomechanics

Author(s): Markus Aspelmeyer, Tobias J. Kippenberg, and Florian MarquardtThe field of cavity optomechanics is reviewed. This field explores the interaction between electromagnetic radiation and nanome … - Dielectric laser accelerators

Author(s): R. Joel England et al.The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing inter … - Hidden symmetries of dynamics in classical and quantum physics

Author(s): Marco CarigliaThis article reviews the role of hidden symmetries of dynamics in the study of physical systems, from the basic concepts of symmetries in phase space to the forefront of curre … - Colloquium: Quantum root-mean-square error and measurement uncertainty relations

Author(s): Paul Busch, Pekka Lahti, and Reinhard F. WernerRecent years have witnessed a controversy over Heisenberg’s famous error-disturbance relation. Here the conflict is resolved by way of an anal … - Quantum channels and memory effects

Author(s): Filippo Caruso, Vittorio Giovannetti, Cosmo Lupo, and Stefano ManciniAny physical process can be represented as a quantum channel mapping an initial state to a final state. Hence it can be … - Colloquium: Emergent properties in plane view: Strong correlations at oxide interfaces

Author(s): Jak Chakhalian, John W. Freeland, Andrew J. Millis, Christos Panagopoulos, and James M. RondinelliFinding new collective electronic states in materials is one of the fundamental goals of co … - Colloquium: Fractional calculus view of complexity: A tutorial

Author(s): Bruce J. WestThe fractional calculus has been part of the mathematics and science literature for 310 years. However, it is only in the past decade or so that it has drawn the attention of m … - Editorial: PRX Takes on a New Role

Author(s): Gene D. Sprouse[Rev. Mod. Phys. 86, 1187] Published Thu Oct 09, 2014 - Spin-polarized quantum confinement in nanostructures: Scanning tunneling microscopy

Author(s): Hirofumi Oka, Oleg O. Brovko, Marco Corbetta, Valeri S. Stepanyuk, Dirk Sander, and Jürgen KirschnerExperimental investigations of spin-polarized electron confinement in nanostructures by s … - Erratum: Nonequilibrium fluctuations, fluctuation theorems, and counting statistics in quantum systems [Rev. Mod. Phys. 81, 1665 (2009)]

Author(s): Massimiliano Esposito, Upendra Harbola, and Shaul Mukamel[Rev. Mod. Phys. 86, 1125] Published Mon Sep 22, 2014 - Colloquium: Nonlinear metamaterials

Author(s): Mikhail Lapine, Ilya V. Shadrivov, and Yuri S. KivsharThis Colloquium presents an overview of the research on nonlinear electromagnetic metamaterials. The developed theoretical approaches a … - The hadronic final state at HERA

Author(s): Paul R. Newman and Matthew WingThe hadronic final state in electron-proton collisions at HERA has provided a rich testing ground for development of the theory of the strong force, QCD. In t … - Modeling semiflexible polymer networks

Author(s): C. P. Broedersz and F. C. MacKintoshThis is an overview of theoretical approaches to semiflexible polymers and their networks. Such semiflexible polymers have large bending rigidities that … - Colloquium: Graphene spectroscopy

Author(s): D. N. Basov, M. M. Fogler, A. Lanzara, Feng Wang, and Yuanbo Zhang (张远波)Spectroscopic studies of electronic phenomena in graphene are reviewed. A variety of methods and techniques are surve … - Colloquium: Biophysical principles of undulatory self-propulsion in granular media

Author(s): Daniel I. GoldmanBiological locomotion, movement within environments through self-deformation, encompasses a range of time and length scales in an organism. These include the electrophysiol … - Beam by design: Laser manipulation of electrons in modern accelerators

Author(s): Erik Hemsing, Gennady Stupakov, Dao Xiang, and Alexander ZholentsAccelerator-based light sources such as storage rings and free-electron lasers use relativistic electron beams to produce in … - Spin-dependent phenomena and device concepts explored in (Ga,Mn)As

Author(s): T. Jungwirth, J. Wunderlich, V. Novák, K. Olejník, B. L. Gallagher, R. P. Campion, K. W. Edmonds, A. W. Rushforth, A. J. Ferguson, and P. NěmecOver the past two decades, the research of (Ga … - Nobel Lecture: The BEH mechanism and its scalar boson

Author(s): François Englert[Rev. Mod. Phys. 86, 843] Published Thu Jul 03, 2014 - Nobel Lecture: Evading the Goldstone theorem

Author(s): Peter W. Higgs[Rev. Mod. Phys. 86, 851] Published Thu Jul 03, 2014 - Publisher’s Note: Bell nonlocality [Rev. Mod. Phys. 86, 419 (2014)]

Author(s): Nicolas Brunner, Daniel Cavalcanti, Stefano Pironio, Valerio Scarani, and Stephanie Wehner[Rev. Mod. Phys. 86, 839] Published Mon Jun 30, 2014 - Publisher’s Note: Phonon-glass electron-crystal thermoelectric clathrates: Experiments and theory [Rev. Mod. Phys. 86, 669 (2014)]

Author(s): Toshiro Takabatake, Koichiro Suekuni, Tsuneyoshi Nakayama, and Eiji Kaneshita[Rev. Mod. Phys. 86, 841] Published Mon Jun 30, 2014 - Nonequilibrium dynamical mean-field theory and its applications

Author(s): Hideo Aoki, Naoto Tsuji, Martin Eckstein, Marcus Kollar, Takashi Oka, and Philipp WernerThe study of nonequilibrium phenomena in correlated lattice systems has developed into one of the mos … - Phonon-glass electron-crystal thermoelectric clathrates: Experiments and theory

Author(s): Toshiro Takabatake, Koichiro Suekuni, Tsuneyoshi Nakayama, and Eiji KaneshitaType-I clathrate compounds have attracted a great deal of interest in connection with the search for efficient t … - Insect flight dynamics: Stability and control

Author(s): Mao SunInsects can hover, fly forward, climb, and descend with ease while demonstrating amazing stability, and they can also maneuver in impressive ways as no other organisms can. Is their … - Real-space renormalization in statistical mechanics

Author(s): Efi Efrati, Zhe Wang, Amy Kolan, and Leo P. KadanoffThis review compares the conceptualization and practice of early real-space renormalization group methods with the conceptualization of m … - Bose-Einstein condensation in quantum magnets

Author(s): Vivien Zapf, Marcelo Jaime, and C. D. BatistaThis article reviews experimental and theoretical work on Bose-Einstein condensation in quantum magnets. These magnets are natural realizations … - Crystalline color superconductors

Author(s): Roberto Anglani, Roberto Casalbuoni, Marco Ciminale, Nicola Ippolito, Raoul Gatto, Massimo Mannarelli, and Marco RuggieriInhomogeneous superconductors and inhomogeneous superfluids appear i … - Standard model Higgs boson searches through the 125 GeV boson discovery

Author(s): Gregorio Bernardi and Matthew HerndonThe experimental searches for the standard model Higgs boson are reviewed from the 2 TeV run of the Tevatron with ≃10 fb−1 of recorded data, and from t … - Bell nonlocality

Author(s): Nicolas Brunner, Daniel Cavalcanti, Stefano Pironio, Valerio Scarani, and Stephanie WehnerBell’s 1964 theorem, which states that the predictions of quantum theory cannot be accounted for by … - 1/f noise: Implications for solid-state quantum information

Author(s): E. Paladino, Y. M. Galperin, G. Falci, and B. L. AltshulerThe efficiency of the future devices for quantum information processing is limited mostly by the finite decoherence rates of the in … - First-principles calculations for point defects in solids

Author(s): Christoph Freysoldt, Blazej Grabowski, Tilmann Hickel, Jörg Neugebauer, Georg Kresse, Anderson Janotti, and Chris G. Van de WallePoint defects and impurities strongly affect the physical pr … - Colloquium: Understanding quantum weak values: Basics and applications

Author(s): Justin Dressel, Mehul Malik, Filippo M. Miatto, Andrew N. Jordan, and Robert W. BoydSince its introduction 25 years ago, the quantum weak value has gradually transitioned from a theoretical … - Recent developments in heavy-ion fusion reactions

Author(s): B. B. Back, H. Esbensen, C. L. Jiang, and K. E. RehmIn this review the main advances in heavy-ion fusion research that have taken place over the last decade are addressed. During this perio … - Dilute ferromagnetic semiconductors: Physics and spintronic structures

Author(s): Tomasz Dietl and Hideo OhnoThis review compiles results of experimental and theoretical studies on thin films and quantum structures of semiconductors with randomly distributed Mn ions, whi … - Quantum simulation

Author(s): I. M. Georgescu, S. Ashhab, and Franco NoriSimulating quantum mechanics is known to be a difficult computational problem, especially when dealing with large systems. However, this difficult … - Gravitational radiation detection with laser interferometry

Author(s): Rana X. AdhikariGravitational-wave detection has been pursued relentlessly for over 40 years. With the imminent operation of a new generation of laser interferometers, it is expected that d … - Galaxy masses

Author(s): Stéphane Courteau, Michele Cappellari, Roelof S. de Jong, Aaron A. Dutton, Eric Emsellem, Henk Hoekstra, L. V. E. Koopmans, Gary A. Mamon, Claudia Maraston, Tommaso Treu, and Lawrence M. Wi … - Secular evolution in disk galaxies

Author(s): J. A. SellwoodDisk galaxies evolve over time through processes that may rearrange both the radial mass profile and the metallicity distribution within the disk. This review of such slow cha … - Quantum-Bayesian coherence

Author(s): Christopher A. Fuchs and Rüdiger SchackIn the quantum-Bayesian interpretation of quantum theory (or QBism), the Born rule cannot be interpreted as a rule for setting measurement-outcome pro … - Fermi gases in one dimension: From Bethe ansatz to experiments

Author(s): Xi-Wen Guan, Murray T. Batchelor, and Chaohong LeeThis article reviews theoretical and experimental developments for one-dimensional Fermi gases. Specifically, the experimentally realized t … - Defect identification in semiconductors with positron annihilation: Experiment and theory

Author(s): Filip Tuomisto and Ilja MakkonenPositron annihilation spectroscopy is particularly suitable for studying vacancy-type defects in semiconductors. Combining state-of-the-art experimental and … - Colloquium: Annual modulation of dark matter

Author(s): Katherine Freese, Mariangela Lisanti, and Christopher SavageDirect detection experiments, which are designed to detect the scattering of dark matter off nuclei in detectors, are a critical … - Colloquium: Beta-delayed fission of atomic nuclei

Author(s): Andrei N. Andreyev, Mark Huyse, and Piet Van DuppenThis Colloquium reviews the studies of exotic type of low-energy nuclear fission, the β-delayed fission (βDF). Emphasis is made on the new … - Colloquium: Laser probing of neutron-rich nuclei in light atoms

Author(s): Z.-T. Lu, P. Mueller, G. W. F. Drake, W. Nörtershäuser, Steven C. Pieper, and Z.-C. YanThe neutron-rich He6 and He8 isotopes exhibit an exotic nuclear structure that consists of a tightly b … - Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

Author(s): Shin’ichiro Ando et al.Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, inclu … - Single-electron current sources: Toward a refined definition of the ampere

Author(s): Jukka P. Pekola, Olli-Pentti Saira, Ville F. Maisi, Antti Kemppinen, Mikko Möttönen, Yuri A. Pashkin, and Dmitri V. AverinThe control of electrons at the level of the elementary charge e wa … - Colloquium: Artificial spin ice: Designing and imaging magnetic frustration

Author(s): Cristiano Nisoli, Roderich Moessner, and Peter SchifferFrustration, the presence of competing interactions, is ubiquitous in the physical sciences and is a source of degeneracy and disorder …