Related papers: Witten effect in a crystalline topological insulat…
The Witten effect tells that a unit magnetic monopole can bind a half elementary charge in an axion media. We present an exact solution of a magnetic monopole in a topological insulator that was proposed to be an axion media recently. It is…
We explore novel topological responses and axion-like phenomena in three-dimensional insulating systems with spacetime-dependent mass terms encoding domain walls. Via a dimensional-reduction approach, we derive a new axion-electromagnetic…
The non-trivial third homotopy class of three-dimensional topological insulators leads to quantized, magneto-electric coefficient or axion angle $\theta= n \pi$, with $n \in \mathbb{Z}$. In Part I, we developed tools for computing $n$ from…
The Witten effect predicts that a magnetic monopole acquires a fractional electric charge inside topological insulators. In this work, we give a microscopic description of this phenomenon, as well as an analogous two-dimensional system with…
In this article, we analyze a magnetic monopole in topological insulators. The monopole obtain a fractional electric charge because of the Witten effect. We consider this system with a microscopic view by adding the Wilson term to the…
The $\theta$-vacua of a gauge theory admit an equivalent formulation as vacua of a massless Chern-Simons $3$-form, which originate from the topological susceptibility of the vacuum. This formulation provides a framework in which the…
We consider a compact abelian Higgs model in 3+1 dimensions with a topological axion term and construct its dual theories for both bulk and boundary at strong coupling. The model may be viewed as describing a superconductor with magnetic…
We study the role of "$\theta$ terms" in the action for three-dimensional $U(1)$ symmetric tensor gauge theories, describing quantum phases of matter hosting gapless higher-spin gauge modes and gapped subdimensional particle excitations,…
The Maxwell equations imply that, under the background of non-zero $\boldsymbol{B}$, varying $\theta$ term produces $\boldsymbol{E} \cdot \boldsymbol{B}$. An interesting example is the Witten effect where a magnetic monopole becomes a dyon…
We show that axions interacting with abelian gauge fields obtain a potential from loops of magnetic monopoles. This is a consequence of the Witten effect: the axion field causes the monopoles to acquire an electric charge and alters their…
We study a phenomenon that electric charges are "teleported" between two spatially separated objects without exchanging charged particles at all. For example, this phenomenon happens between a magnetic monopole and an axion string in four…
We investigate the electromagnetic fields produced by the oscillating point electric or magnetic dipole placed in a spherical volume with nonzero time-independent effective axion field. Our analytical solution shows that the fields outside…
The electromagnetic response of topological insulators is governed by axion electrodynamics, which features a topological magnetoelectric term in the Maxwell equations. As a consequence magnetic fields become the source of electric fields…
We explore a model akin to axion electrodynamics in which the axion field $\theta (t,\mathbf{x})$ rather than being dynamical is a piecewise constant effective parameter $\theta$ encoding the microscopic properties of the medium inasmuch as…
Topological insulators (TIs) in three space dimensions can be characterized by a quantized magnetoelectric coefficient. However, this coupling does not have experimentally observable consequences in the presence of time-reversal symmetry,…
One of the intriguing properties characteristic to three-dimensional topological materials is the topological magnetoelectric phenomena arising from a topological term called the $\theta$ term. Such magnetoelectric phenomena are often…
In this contribution we revisit the lattice discretization of the topological charge for abelian lattice field theories. The construction departs from an initially non-compact discretization of the gauge fields and after absorbing $2\pi$…
It is well-known that one signature of the three-dimensional electron topological insulator is the Witten effect: if the system is coupled to a compact electromagnetic gauge field, a monopole in the bulk acquires a half-odd-integer…
The orbital motion of electrons in a three-dimensional solid can generate a pseudoscalar magnetoelectric coupling $\theta$, a fact we derive for the single-particle case using a recent theory of polarization in weakly inhomogeneous…
Based on a first-principles approach, we show that in a single crystal of a prototypical topological insulator such as Bi$_2$Se$_3$ the difference in the work function between adjacent surfaces with different crystal-face orientations…