Multichannel Kondo Anyons for topological Quantum Computation

APA

Komijani, Y. (2020). Multichannel Kondo Anyons for topological Quantum Computation. Perimeter Institute for Theoretical Physics. https://pirsa.org/20010098

MLA

Komijani, Yashar. Multichannel Kondo Anyons for topological Quantum Computation. Perimeter Institute for Theoretical Physics, Jan. 30, 2020, https://pirsa.org/20010098

BibTex

          @misc{ scivideos_PIRSA:20010098,
            doi = {10.48660/20010098},
            url = {https://pirsa.org/20010098},
            author = {Komijani, Yashar},
            keywords = {Quantum Matter},
            language = {en},
            title = {Multichannel Kondo Anyons for topological Quantum Computation},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2020},
            month = {jan},
            note = {PIRSA:20010098 see, \url{https://scivideos.org/pirsa/20010098}}
          }
          

Yashar Komijani Rutgers University

Source Repository PIRSA
Collection

Abstract

I propose [1] to use the residual anyons of overscreened Kondo physics for quantum computation. A superconducting proximity gap of Δ<TK can be utilized to isolate the anyon from the continuum of excitations and stabilize the non-trivial fixed point. We use the dynamical large-N technique [2] and bosonization to show that the residual entropy survives in a superconductor and suggest a charge Kondo setup for isolating and detecting the Majorana fermion in the two-channel Kondo impurity.
I will then conjecture that topological defects in a multichannel Kondo lattice carry anyons. Motivated by this, we look at a two-channel SU(N) Kondo lattice in the large-N limit [3].  In this model, the continuous channel-symmetry is spontaneously broken, forming a “channel ferromagnet” and realizing the so-called fractionalized order parameter [4]. By integrating out the fermions we derive an effective action that describes the symmetry breaking and its emergent collective modes. Remarkably, topological defects in the order parameter carry a U(1) flux, manifested in the Aharonov-Bohm phase picked by electrons that orbit the defect. We argue that the phase diagram contains a non-magnetic transition between a large and a small Fermi surface.
I will also briefly highlight our recent results [5] on a magnetically frustrated Kondo-screened triangle which contains two symmetry-preserving phases, transcending the Landau-Ginzburg paradigm. The quantum phase transition is driven by the proliferation of instantons of the emergent gauge theory and can be regarded as a toy model for the deconfined criticality.