Related papers: Screening Clouds and Majorana Fermions
After a recent series of rapid and exciting developments, the long search for the Majorana fermion - the elusive quantum entity at the border between particles and antiparticles - has produced the first positive experimental results, but is…
We study how finite size effects may appear when a quantum dot in the Kondo Coulomb blockade regime is embedded into a mesoscopic device with finite wires. These finite size effects appear when the size of the mesoscopic device containing…
It is shown that the presence of the Majorana fermion edge states along the perimeter of a topological superconductor can be probed using an interacting quantum dot coupled to three terminals: two spin-polarized (ferromagnetic) leads and…
We apply conformal field theory analysis to the $k$-channel SU($N$) Kondo system, and find a peculiar behavior in the cases $N > k > 1$, which we call Fermi/non-Fermi mixing: The low temperature scaling is described as the Fermi liquid,…
The functional renormalization group provides an efficient description of the interplay and competition of correlations on different energy scales in interacting Fermi systems. An exact hierarchy of flow equations yields the gradual…
The Kondo effect involves the formation of a spin singlet by a magnetic impurity and conduction electrons. It is characterized by a low temperature scale, the Kondo temperature, $T_K$, and an associated long length scale, $\xi_K = \hbar…
The pseudogap Kondo problem, describing a magnetic impurity embedded in an electronic environment with a power-law density of states, displays continuous quantum phase transitions between free and screened moment phases. In this paper we…
A theoretical concept is presented for the screening of several magnetic moments locally exchange coupled to conduction electrons in a metallic nanostructure. We consider a quantum confined multi-impurity Kondo model which exhibits the…
The spatial length of the Kondo screening is still a controversial issue related to Kondo physics. While renormalization group and Bethe Anzats solutions have provided detailed information about the thermodynamics of magnetic impurities,…
We consider a magnetic impurity deposited on the surface of a strong topological insulator and interacting with the surface modes by a Kondo exchange interaction. Taking into account the warping of the Fermi line of the surface modes, we…
We propose to use residual parafermions of the overscreened Kondo effect for topological quantum computation. A superconducting proximity gap of $\Delta<T_K$ can be utilized to isolate the parafermion from the continuum of excitations and…
We analyze the single-channel Kondo model using the recently developed unitary renormalization group (URG) method, and obtain a comprehensive understanding of the Kondo screening cloud. The fixed-point low-energy Hamiltonian enables the…
A many-body resonance emerges at the Fermi energy when an electron bath screens the magnetic moment of a half-filled impurity level. This Kondo effect, originally introduced to explain the abnormal resistivity behavior in bulk magnetic…
We study a quantum impurity coupled to the edge states of a two-dimensional helical topological superconductor, i.e., to a pair of counterpropagating Majorana fermion edge channels with opposite spin polarizations. For an impurity described…
Unambiguous identification of Majorana physics presents an outstanding problem whose solution could render topological quantum computing feasible. We develop a numerical approach to treat finite-size superconducting chains supporting…
The screening of an impurity spin in the Kondo model occurs over a characteristic length scale $\xi_K$, that defines the size of the Kondo screening cloud or ``mist". The presence of such a length sc A consistent way to show the presence of…
Topological Majorana fermion (MF) quasiparticles have been recently suggested to exist in semiconductor quantum wires with proximity induced superconductivity and a Zeeman field. Although the experimentally observed zero bias tunneling peak…
The model of two-level Kondo effect is studied by the Wilson numerical renormalization group method. It is shown that there exist a new type of weak-coupling fixed point other than the strong-coupling fixed point found by Vladar and…
Despite extensive experimental efforts over the past two decades, the quest for Majorana fermions in superconductors remains inconclusive. We propose an experimental method that can conclusively confirm, or rule out, the existence of these…
The Kondo problem, which describes the interaction of a spin $s$ magnetic impurity with a free Fermi gas, is a classic example of strongly coupled physics. Historically, the problem has been solved by Wilson's numerical renormalization…