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R.r. Metsaev - One of the best experts on this subject based on the ideXlab platform.
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Light-cone continuous-Spin Field in AdS space
Physics Letters B, 2019Co-Authors: R.r. MetsaevAbstract:Abstract We develop further the general light-cone gauge approach in AdS space and apply it for studying continuous-Spin Field. For such Field, we find light-cone gauge Lagrangian and realization of relativistic symmetries. We find a simple realization of Spin operators entering our approach. Generalization of our results to the gauge invariant Lagrangian formulation is also described. We conjecture that, in the framework of AdS/CFT, the continuous-Spin AdS Field is dual to light-ray conformal operator. For some particular cases, our continuous-Spin Field leads to reducible models. We note two reducible models. The first model consists of massive scalar, massless vector, and partial continuous-Spin Field involving Fields of all Spins greater than one, while the second model consists of massive vector, massless Spin-2 Field, and partial continuous-Spin Field involving all Fields of Spins greater than two.
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Cubic interaction vertices for massive/massless continuous-Spin Fields and arbitrary Spin Fields
Journal of High Energy Physics, 2018Co-Authors: R.r. MetsaevAbstract:We use light-cone gauge formalism to study interacting massive and massless continuous-Spin Fields and finite component arbitrary Spin Fields propagating in the flat space. Cubic interaction vertices for such Fields are considered. We obtain parity invariant cubic vertices for coupling of one continuous-Spin Field to two arbitrary Spin Fields and cubic vertices for coupling of two continuous-Spin Fields to one arbitrary Spin Field. Parity invariant cubic vertices for self-interacting massive/massless continuous-Spin Fields are also obtained. We find the complete list of parity invariant cubic vertices for continuous-Spin Fields and arbitrary Spin Fields.
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BRST-BV approach to continuous-Spin Field
Physics Letters B, 2018Co-Authors: R.r. MetsaevAbstract:Abstract Using BRST-BV approach, massless and massive continuous-Spin Fields propagating in the flat space are studied. For such Fields, BRST-BV gauge invariant Lagrangian is obtained. The Lagrangian and gauge transformations are constructed out of traceless gauge Fields and traceless gauge transformation parameters. Interrelation between the BRST-BV Lagrangian and the Lagrangian for the continuous-Spin Fields in metric-like approach is demonstrated. Considering the BRST-BV Lagrangian in the Siegel gauge, we get gauge-fixed Lagrangian which is invariant under global BRST and antiBRST transformations.
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fermionic continuous Spin gauge Field in a ds space
Physics Letters B, 2017Co-Authors: R.r. MetsaevAbstract:Abstract Fermionic continuous Spin Field propagating in (A)dS space–time is studied. Gauge invariant Lagrangian formulation for such fermionic Field is developed. Lagrangian of the fermionic continuous Spin Field is constructed in terms of triple gamma-traceless tensor–Spinor Dirac Fields, while gauge symmetries are realized by using gamma-traceless gauge transformation parameters. It is demonstrated that partition function of fermionic continuous Spin Field is equal to one. Modified de Donder gauge condition that considerably simplifies analysis of equations of motion is found. Decoupling limits leading to arbitrary Spin massless, partial-massless, and massive fermionic Fields are studied.
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continuous Spin gauge Field in a ds space
Physics Letters B, 2017Co-Authors: R.r. MetsaevAbstract:Abstract Totally symmetric continuous Spin Field propagating in (A)dS is studied. Lagrangian gauge invariant formulation for such Field is developed. Lagrangian of continuous Spin Field is constructed in terms of double traceless tensor Fields, while gauge transformations are constructed in terms of traceless gauge transformation parameters. de Donder like gauge condition that leads to simple gauge fixed Lagrangian is found. Gauge-fixed Lagrangian invariant under global BRST transformations is presented. The BRST Lagrangian is used for computation of a partition function. It is demonstrated that the partition function of the continuous Spin Field is equal to one. Various decoupling limits of the continuous Spin Field are also studied.
I. L. Buchbinder - One of the best experts on this subject based on the ideXlab platform.
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Massless Infinite Spin (Super)particles and Fields
Proceedings of the Steklov Institute of Mathematics, 2020Co-Authors: I. L. Buchbinder, A. P. Isaev, S. A. FedorukAbstract:A new twistor Field formulation of a model of a massless infinite Spin particle is proposed. A twistor infinite Spin Field is found, and its helicity decomposition is obtained. Twistorial equations of motion for infinite Spin Fields are derived in the cases of integer and half-integer helicities. The infinite integer Spin Field and infinite half-integer Spin Field are shown to form an N = 1 infinite Spin supermultiplet. The corresponding supersymmetry transformations are presented. It is proved that the supersymmetry algebra is closed on-shell.
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twistorial and space time descriptions of massless infinite Spin super particles and Fields
Nuclear Physics, 2019Co-Authors: I. L. Buchbinder, A. P. Isaev, S. A. FedorukAbstract:Abstract We develop a new twistorial Field formulation of a massless infinite Spin particle. Unlike our previous approach arXiv:1805.09706 , the quantization of such a world-line infinite Spin particle model is carried without any gauge fixing. As a result, we construct a twistorial infinite Spin Field and derive its helicity decomposition. Using the Field twistor transform, we construct the space-time infinite (continuous) Spin Field, which depends on the coordinate four-vector and additional commuting Weyl Spinor. The equations of motion for infinite Spin Fields in the cases of integer and half-integer helicities are derived. We show that the infinite integer-Spin Field and infinite half-integer-Spin Field form the N = 1 infinite Spin supermultiplet. The corresponding supersymmetry transformations are formulated and their on-shell algebra is derived. As a result, we find the Field realization of the infinite Spin N = 1 supersymmetry.
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Quartet unconstrained formulation for massive higher Spin Fields
Journal of High Energy Physics, 2008Co-Authors: I. L. Buchbinder, Anton GalajinskyAbstract:We generalize the unconstrained description of free massless higher Spin Fields previously developed in [Nucl.Phys. B 779 (2007) 155] to the case of free massive higher Spin Fields in a flat space of arbitrary dimension. The Lagrangian is given in an easy-to-handle form for an arbitrary value of Spin. It is local, free from higher derivative terms, and involves a minimal number of auxiliary Fields needed for an unconstrained gauge invariant description of a free massive higher Spin Field in arbitrary dimension.Comment: V2: discussion extended, acknowledgements and references adde
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Gauge invariant Lagrangian construction for massive higher Spin fermionic Fields
Physics Letters B, 2006Co-Authors: I. L. Buchbinder, V.a. Krykhtin, L.l. Ryskina, H. TakataAbstract:Abstract We formulate a general gauge invariant Lagrangian construction describing the dynamics of massive higher Spin fermionic Fields in arbitrary dimensions. Treating the conditions determining the irreducible representations of Poincare group with given Spin as the operator constraints in auxiliary Fock space, we built the BRST charge for the model under consideration and find the gauge invariant equations of motion in terms of vectors and operators in the Fock space. It is shown that like in massless case [I.L. Buchbinder, V.A. Krykhtin, A. Pashnev, Nucl. Phys. B 711 (2005) 367, hep-th/0410215 ], the massive fermionic higher Spin Field models are the reducible gauge theories and the order of reducibility grows with the value of Spin. In compare with all previous approaches, no off-shell constraints on the Fields and the gauge parameters are imposed from the very beginning, all correct constraints emerge automatically as the consequences of the equations of motion. As an example, we derive a gauge invariant Lagrangian for massive Spin 3/2 Field.
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lagrangian formulation of the massless higher integer Spin Fields in the ads background
Physics Letters B, 2001Co-Authors: I. L. Buchbinder, A Pashnev, Mirian TsulaiaAbstract:Abstract We construct the Lagrangian description of arbitrary integer higher-Spin massless Fields on the background of the D-dimensional anti-de Sitter space. The operator constraints in auxiliary Fock space corresponding to subsidiary conditions for irreducible unitary massless representations of the D-dimensional anti-de Sitter group are formulated. Unlike flat space, the algebra of the constraints turns out to be nonlinear and analogous to the W 3 algebra. We construct the nilpotent BRST charge for this nonlinear algebra and derive on its basis the correct Field content and gauge invariant action describing the consistent arbitrary integer-Spin Field dynamics in AdS space.
Xiaofeng Qian - One of the best experts on this subject based on the ideXlab platform.
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electrically tunable high curie temperature two dimensional ferromagnetism in van der waals layered crystals
Applied Physics Letters, 2020Co-Authors: Hua Wang, Xiaofeng QianAbstract:Identifying intrinsic low-dimensional ferromagnets with high magnetic transition temperature and electrically tunable magnetism is crucial for the development of miniaturized Spintronics and magnetoelectrics. Recently, long-range 2D ferromagnetism was observed in van der Waals crystals CrI3 and Cr2Ge2Te6, however, their Curie temperature is significantly lowered when reducing down to monolayer/few layers. Herein, using renormalized Spin-wave theory and first-principles electronic structure theory, we present a theoretical study of electrically tunable 2D ferromagnetism in van der Waals layered CrSBr and CrSeBr semiconductors with a high Curie temperature of ∼150 K and a sizable bandgap. The high transition temperature is attributed to the strong anion-mediated superexchange interaction and a sizable Spin-wave excitation gap due to large exchange and single-ion anisotropy. Remarkably, hole and electron doping can switch the magnetization easy axis from the in-plane to the out-of-plane direction. These unique characteristics establish monolayer CrSBr and CrSeBr as a promising platform for realizing 2D Spintronics and magnetoelectrics such as 2D Spin valves and Spin Field effect transistors.
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electrically tunable high curie temperature two dimensional ferromagnetism in van der waals layered crystals
arXiv: Materials Science, 2020Co-Authors: Hua Wang, Xiaofeng QianAbstract:Identifying intrinsic low-dimensional ferromagnets with high transition temperature and electrically tunable magnetism is crucial for the development of miniaturized Spintronics and magnetoelectrics. Recently long-range 2D ferromagnetism was observed in van der Waals crystals CrI$_3$ and Cr$_2$Ge$_2$Te$_6$, however their Curie temperature is significantly lowered when reducing down to monolayer/few layers. Herein, using renormalized Spin-wave theory and first-principles electronic structure theory, we present a theoretical study of electrically tunable 2D ferromagnetism in van der Waals layered CrSBr and CrSeBr semiconductors with high Curie temperature of ~150K and sizable band gap. High transition temperature is attributed to strong anion-mediated superexchange interaction and a sizable Spin-wave excitation gap due to large exchange and single-ion anisotropy. Remarkably, hole and electron doping can switch magnetization easy axis from in-plane to out-of-plane direction. These unique characteristics establish monolayer CrSBr and CrSeBr as promising platform for realizing 2D Spintronics and magnetoelectrics such as 2D Spin Field effect transistor.
John D. Budai - One of the best experts on this subject based on the ideXlab platform.
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advances in wide bandgap materials for semiconductor Spintronics
Materials Science & Engineering R-reports, 2003Co-Authors: Stephen Pearton, David P. Norton, C. R. Abernathy, Arthur F. Hebard, Y. D. Park, Lynn A. Boatner, John D. BudaiAbstract:Abstract Existing semiconductor electronic and photonic devices utilize the charge on electrons and holes in order to perform their specific functionality such as signal processing or light emission. The relatively new Field of semiconductor Spintronics seeks, in addition, to exploit the Spin of charge carriers in new generations of transistors, lasers and integrated magnetic sensors. The ability to control of Spin injection, transport and detection leads to the potential for new classes of ultra-low power, high speed memory, logic and photonic devices. The utility of such devices depends on the availability of materials with practical (>300 K) magnetic ordering temperatures. In this paper, we summarize recent progress in dilute magnetic semiconductors (DMS) such as (Ga, Mn)N, (Ga, Mn)P, (Zn, Mn)O and (Zn, Mn)SiGeN2 exhibiting room temperature ferromagnetism, the origins of the magnetism and its potential applications in novel devices such as Spin-polarized light emitters and Spin Field effect transistors.
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Advances in wide bandgap materials for semiconductor Spintronics
Materials Science and Engineering R: Reports, 2003Co-Authors: Stephen Pearton, David P. Norton, C. R. Abernathy, Arthur F. Hebard, Y. D. Park, Lynn A. Boatner, John D. BudaiAbstract:Existing semiconductor electronic and photonic devices utilize the charge on electrons and holes in order to perform their specific functionality such as signal processing or light emission. The relatively new Field of semiconductor Spintronics seeks, in addition, to exploit the Spin of charge carriers in new generations of transistors, lasers and integrated magnetic sensors. The ability to control of Spin injection, transport and detection leads to the potential for new classes of ultra-low power, high speed memory, logic and photonic devices. The utility of such devices depends on the availability of materials with practical (>300 K) magnetic ordering temperatures. In this paper, we summarize recent progress in dilute magnetic semiconductors (DMS) such as (Ga, Mn)N, (Ga, Mn)P, (Zn, Mn)O and (Zn, Mn)SiGeN2exhibiting room temperature ferromagnetism, the origins of the magnetism and its potential applications in novel devices such as Spin-polarized light emitters and Spin Field effect transistors. © 2003 Elsevier Science B.V. All rights reserved.
Mirian Tsulaia - One of the best experts on this subject based on the ideXlab platform.
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On the tensionless limit of string theory, off-shell higher Spin interaction vertices and BCFW recursion relations
Journal of High Energy Physics, 2010Co-Authors: Angelos Fotopoulos, Mirian TsulaiaAbstract:We construct an off-shell extension of cubic interaction vertices between massless bosonic Higher Spin Fields on a flat background which can be obtained from perturbative bosonic string theory. We demonstrate how to construct higher quartic interaction vertices using a simple particular example. We examine whether BCFW recursion relations for interacting Higher Spin theories are applicable. We argue that for several interesting examples such relations should exist, but consistency of the theories might require that we supplement Higher Spin Field theories with extended and possibly non-local objects.
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Dynamics of Higher Spin Fields and Tensorial Space
Journal of High Energy Physics, 2005Co-Authors: Igor A. Bandos, Xavier Bekaert, Dmitri Sorokin, J. A. De Azcárraga, Mirian TsulaiaAbstract:The structure and the dynamics of massless higher Spin Fields in various dimensions are reviewed with an emphasis on conformally invariant higher Spin Fields. We show that in D=3,4,6 and 10 dimensional space-time the conformal higher Spin Fields constitute the quantum spectrum of a twistor-like particle propagating in tensorial spaces of corresponding dimensions. We give a detailed analysis of the Field equations of the model and establish their relation with known formulations of free higher Spin Field theory.
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lagrangian formulation of the massless higher integer Spin Fields in the ads background
Physics Letters B, 2001Co-Authors: I. L. Buchbinder, A Pashnev, Mirian TsulaiaAbstract:Abstract We construct the Lagrangian description of arbitrary integer higher-Spin massless Fields on the background of the D-dimensional anti-de Sitter space. The operator constraints in auxiliary Fock space corresponding to subsidiary conditions for irreducible unitary massless representations of the D-dimensional anti-de Sitter group are formulated. Unlike flat space, the algebra of the constraints turns out to be nonlinear and analogous to the W 3 algebra. We construct the nilpotent BRST charge for this nonlinear algebra and derive on its basis the correct Field content and gauge invariant action describing the consistent arbitrary integer-Spin Field dynamics in AdS space.
