scholarly journals Near-conformal dynamics at large charge

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
Domenico Orlando ◽  
Susanne Reffert ◽  
Francesco Sannino
2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Alba Grassi ◽  
Zohar Komargodski ◽  
Luigi Tizzano

Abstract We study the correlation functions of Coulomb branch operators of four-dimensional $$ \mathcal{N} $$ N = 2 Superconformal Field Theories (SCFTs). We focus on rank-one theories, such as the SU(2) gauge theory with four fundamental hypermultiplets. “Extremal” correlation functions, involving exactly one anti-chiral operator, are perhaps the simplest nontrivial correlation functions in four-dimensional Quantum Field Theory. We show that the large charge limit of extremal correlators is captured by a “dual” description which is a chiral random matrix model of the Wishart-Laguerre type. This gives an analytic handle on the physics in some particular excited states. In the limit of large random matrices we find the physics of a non-relativistic axion-dilaton effective theory. The random matrix model also admits a ’t Hooft expansion in which the matrix is taken to be large and simultaneously the coupling is taken to zero. This explains why the extremal correlators of SU(2) gauge theory obey a nontrivial double scaling limit in states of large charge. We give an exact solution for the first two orders in the ’t Hooft expansion of the random matrix model and compare with expectations from effective field theory, previous weak coupling results, and we analyze the non-perturbative terms in the strong ’t Hooft coupling limit. Finally, we apply the random matrix theory techniques to study extremal correlators in rank-1 Argyres-Douglas theories. We compare our results with effective field theory and with some available numerical bootstrap bounds.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yan Song ◽  
Tong-Tong Hu ◽  
Yong-Qiang Wang

Abstract We study the model of four-dimensional Einstein-Maxwell-Λ theory minimally coupled to a massive charged self-interacting scalar field, parameterized by the quartic and hexic couplings, labelled by λ and β, respectively. In the absence of scalar field, there is a class of counterexamples to cosmic censorship. Moreover, we investigate the full nonlinear solution with nonzero scalar field included, and argue that these counterexamples can be removed by assuming charged self-interacting scalar field with sufficiently large charge not lower than a certain bound. In particular, this bound on charge required to preserve cosmic censorship is no longer precisely the weak gravity bound for the free scalar theory. For the quartic coupling, for λ < 0 the bound is below the one for the free scalar fields, whereas for λ > 0 it is above. Meanwhile, for the hexic coupling the bound is always above the one for the free scalar fields, irrespective of the sign of β.


2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Domenico Orlando ◽  
Vito Pellizzani ◽  
Susanne Reffert
Keyword(s):  

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Simeon Hellerman ◽  
Nozomu Kobayashi ◽  
Shunsuke Maeda ◽  
Masataka Watanabe

Abstract As a sequel to previous work, we extend the study of the ground state configuration of the D = 3, Wilson-Fisher conformal O(4) model. In this work, we prove that for generic ratios of two charge densities, ρ1/ρ2, the ground-state configuration is inhomogeneous and that the inhomogeneity expresses itself towards longer spatial periods. This is the direct extension of the similar statements we previously made for ρ1/ρ2 ≪ 1. We also compute, at fixed set of charges, ρ1, ρ2, the ground state energy and the two-point function(s) associated with this inhomogeneous configuration on the torus. The ground state energy was found to scale (ρ1 + ρ2)3/2, as dictated by dimensional analysis and similarly to the case of the O(2) model. Unlike the case of the O(2) model, the ground also strongly violates cluster decomposition in the large-volume, fixed-density limit, with a two-point function that is negative definite at antipodal points of the torus at leading order at large charge.


2008 ◽  
Vol 1071 ◽  
Author(s):  
Chia-Han Yang ◽  
Yue Kuo ◽  
Chen-Han Lin ◽  
Rui Wan ◽  
Way Kuo

AbstractSemiconducting or metallic nanocrystals embedded high-k films have been investigated. They showed promising nonvolatile memory characteristics, such as low leakage currents, large charge storage capacities, and long retention times. Reliability of four different kinds of nanocrystals, i.e., nc- Ru, -ITO, -Si and -ZnO, embedded Zr-doped HfO2 high-k dielectrics have been studied. All of them have higher relaxation currents than the non-embedded high-k film has. The decay rate of the relaxation current is in the order of nc-ZnO > nc-ITO > nc-Si > nc-Ru. When the relaxation currents of the nanocrystals embedded samples were fitted to the Curie-von Schweidler law, the n values were between 0.54 and 0.77, which are much lower than that of the non embedded high-k sample. The nanocrystals retain charges in two different states, i.e., deeply and loosely trapped. The ratio of these two types of charges was estimated. The charge storage capacity and holding strength are strongly influenced by the type of material of the embedded nanocrystals. The nc-ZnO embedded film holds trapped charges longer than other embedded films do. The ramp-relax result indicates that the breakdown of the embedded film came from the breakdown of the bulk high-k film. The type of nanocrystal material influences the breakdown strength.


Author(s):  
Naveen K Tailor ◽  
Yukta . ◽  
Rahul Ranjan ◽  
Sudhir Ranjan ◽  
Tejasvini Sharma ◽  
...  

Metal halide perovskites (MHPs) have recently emerged as an ideal semiconductor for photovoltaic application. Much of the advantageous properties of perovskite is dominated by its large charge carrier mobility (μ)...


2005 ◽  
Vol 19 (15n17) ◽  
pp. 2345-2352 ◽  
Author(s):  
B. MANIL ◽  
P. BODUCH ◽  
A. CASSIMI ◽  
O. KAMALOU ◽  
L. MAUNOURY ◽  
...  

Clusters of C 60 fullerenes are (multi)-ionised in collisions with O 5+ projectiles at a collision energy of 100 keV. The dominant fragmentation channels are analysed by time-of-flight mass spectrometry for different cluster size distributions. Singly charged [Formula: see text], ions are found to be the dominant fragments, in 25% connected with the loss of one or more C 2-units. This result is explained by the large charge mobility in fullerene clusters. Doubly charged fragments, in form of [Formula: see text] and [Formula: see text], contribute to the observed spectrum with less than 5–10% only and are mainly attributed to the fragmentation of dimers. Singly charged small carbon clusters in the size range n = 7 to 19 are formed with low kinetic energies indicating the importance of thermal dissociation processes. The present experiments confirm earlier conclusions on the charge mobility in fullerene clusters.


2019 ◽  
Vol 9 (5) ◽  
pp. 956 ◽  
Author(s):  
Huifeng Shi ◽  
Xianqiang Liu ◽  
Rui Wu ◽  
Yijing Zheng ◽  
Yonghe Li ◽  
...  

In situ scanning electron microscopy (SEM) offers a good way to investigate the structural evolution during lithiation and delithiation processes. In this paper, the dynamical morphological evolution of 3D-line-structured/unstructured Si/C composite electrodes was observed by in situ SEM. The investigation revealed the microstructural origin of large charge capacity for 3D-line-structured anodes. Based on this proposed mechanism, a coarse optimization of 3D-line-structured anodes was proposed. These results shed light on the unique advantages of using an in situ SEM technique when studying realistic bulk batteries and designing 3D electrode structures.


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