Bulletin of the American Physical Society
APS March Meeting 2020
Volume 65, Number 1
Monday–Friday, March 2–6, 2020; Denver, Colorado
Session A07: Topological Quantum ComputingFocus
|
Hide Abstracts |
Sponsoring Units: DQI Room: 102 |
Monday, March 2, 2020 8:00AM - 8:12AM |
A07.00001: Bifurcating entanglement-renormalization group flows of fracton stabilizer models Arpit Dua, Pratyush Sarkar, Dominic Williamson, Meng Cheng We investigate the entanglement-renormalization group flows of translation-invariant topological stabilizer models in three dimensions. Fracton models are observed to bifurcate under entanglement renormalization, generically returning at least one copy of the original model. Based on this behavior we formulate the notion of bifurcated equivalence for fracton phases, generalizing foliated fracton equivalence. The notion of quotient superselection sectors is also generalized accordingly. We calculate bifurcating entanglement-renormalization group flows for a wide range of examples and, based on those results, propose conjectures regarding the classification of translation-invariant topological stabilizer models in three dimensions. |
Monday, March 2, 2020 8:12AM - 8:24AM |
A07.00002: Quantum electrodynamics in a topological metamaterial: Part 1 Eun Jong Kim, Xueyue Zhang, Alp Sipahigil, Vinicius S Ferreira, Jash Banker, Mohammad Mirhosseini, Oskar Painter The rich quantum electrodynamical properties arising from topological photonics open new possibilities for studying novel many-body states and implementing topologically protected quantum information processing protocols. It has been recently suggested that a topological waveguide, which realizes a photonic analog of the Su-Schrieffer-Heeger (SSH) model, can host unconventional quantum optical phenomena [Sci. Adv. 5, eaaw0297 (2019)]. We discuss the implementation of the topological waveguide with superconducting metamaterials. We explore the exotic properties of qubit-photon bound states and topological edge states emergent in this system. |
Monday, March 2, 2020 8:24AM - 8:36AM |
A07.00003: Quantum electrodynamics in a topological metamaterial: Part 2 Xueyue Zhang, Eun Jong Kim, Alp Sipahigil, Vinicius S Ferreira, Jash Banker, Mohammad Mirhosseini, Oskar Painter Topological concepts in photonics give rise to novel ways of controlling light or microwaves. By coupling quantum emitters to topological photonic structures, photon-mediated interaction between the emitters inherits the topological properties, which can lead to novel radiative phenomena. Here, we study superconducting qubits coupled to a microwave metamaterial waveguide which is a photonic analog of the Su-Schrieffer-Heeger (SSH) model [Sci. Adv. 5, eaaw0297 (2019)]. We report the observation of novel interaction profiles and scattering properties of the qubits induced by the topological photonic bath. |
Monday, March 2, 2020 8:36AM - 8:48AM |
A07.00004: Transition from 2D to 1D topological superconductivity in a triangular island of p-wave superconductor Aidan Winblad, Hua Chen
|
Monday, March 2, 2020 8:48AM - 9:00AM |
A07.00005: Time-resolved electrical detection of chiral edge vortex braiding Inanc Adagideli, Fabian Hassler, Aurelien Grabsch, Michal Pacholski, Carlo W J Beenakker A $\bm{2\pi}$ phase shift across a Josephson junction in a topological |
Monday, March 2, 2020 9:00AM - 9:12AM |
A07.00006: Braiding of Majorana Fermions in a Cavity Mircea Trif, Pascal Simon We study the dynamical process of braiding Majorana bound states (MBS) in the presence of the coupling to photons in a microwave cavity. We show theoretically that the π/4 phase associated with the braiding of MBS, as well as the parity of the ground state are imprinted into the photonic field of the cavity, which can be detected by dispersive readout techniques [1]. We use a density matrix description for the dynamics of the low energy states in order to account for various relaxation channels both in the adiabatic regime, as well as within the Floquet formalism in the case of periodic driving. We evaluate the average photon number and the second order photon coherence function g(2)(0), and show they are affected by the non Abelian Berry phase accumulated during the braiding process [2]. These manifestations are purely dynamical, they occur in the absence of any splitting of the MBS that are exchanged, and they disappear in the static setups studied previously. Conversely, the cavity can affect the braiding phase, which in turn should allow for cavity controlled braiding. |
Monday, March 2, 2020 9:12AM - 9:24AM |
A07.00007: Braiding Majorana Fermions and Creating Quantum Logic Gates with Vortices on a Periodic Pinning Structure Xiaoyu Ma, Cynthia Reichhardt, Charles Reichhardt We show how vortices that support Majorana fermions when placed on a periodic pinning array can be used for vortex exchange and independent braiding by performing a series of specific moves with a probe tip. Using these braiding operations, we demonstrate realizations of a Hadamard and a CNOT gate. We specifically consider the first matching field at which there is one vortex per pinning site, and we show that there are two basic dynamic operations, move and exchange, from which basic braiding operations can be constructed in order to create specific logic gates. The periodic pinning array permits both control of the world lines of the vortices and freedom for vortex manipulation using a set of specific moves of the probe during which the probe tip strength and height remain unchanged. We measure the robustness of the different moves against thermal effects and show that the three different operations produce distinct force signatures on the moving tip. |
Monday, March 2, 2020 9:24AM - 9:36AM |
A07.00008: Towards practical self-correction with augmented Majorana stabilizer codes Stephan Plugge, Marcel Franz, Robert Raussendorf, Ian Affleck We present design ideas for an augmented Majorana surface code (MSC) that allows improved error-correcting behavior on practically relevant time-scales. The underlying mechanism resembles that of interacting anyon models, and facilitates the protected Hamiltonian-level generation of stabilizer operators in MSCs together with coupling to auxiliary bosonic degrees of freedom. In this talk, I will discuss MSCs and their extensions affording improved error-correction, towards the goal of thermally stable quantum memories in 2D. |
Monday, March 2, 2020 9:36AM - 9:48AM |
A07.00009: Optimizing Clifford gate generation for measurement-only topological quantum computation with Majorana zero modes Alan Tran, Alex Bocharov, Bela Bauer, Parsa Bonderson One of the main challenges for quantum computation is that while the number of gates required to perform a non-trivial computation may be very large, decoherence and errors in realistic architectures limits the number of physical gate operations that can be performed coherently. Therefore, an optimal mapping of the quantum algorithm into the physically available set of operations is of crucial importance. We examine this problem for a measurement-only topological quantum computer based on Majorana zero modes (MZMs), where gates are performed through sequences of measurements. Such a scheme has been proposed as a practical, scalable approach to process quantum information in an array of topological MZM qubits. Building on previous work that has shown that multi-qubit Clifford gates can be enacted in a topologically protected fashion in such qubit networks, we discuss methods to obtain the optimal measurement sequence for a given Clifford gate under the constraints imposed by the physical architecture, such as layout and the relative difficulty of implementing different measurements. Our methods also provide tools for comparative analysis of different architectures and strategies, given experimental characterizations of particular aspects of the systems under consideration. |
Monday, March 2, 2020 9:48AM - 10:00AM |
A07.00010: Computational universality of symmetry-protected topologically ordered cluster phases on 2D Archimedean lattices Austin Daniel, Rafael Alexander, Akimasa Miyake Which symmetry-protected topologically ordered (SPTO) ground states can be used for universal measurement-based quantum computation in a similar fashion to the 2D cluster state? 2D SPTO states are classified not only by global on-site symmetries but also by subsystem symmetries, which are fine-grained symmetries dependent on the lattice geometry. Recently, all states within so-called SPTO cluster phases on the square and hexagonal lattices have been shown to be universal, based on the presence of subsystem symmetry and associated structures of quantum cellular automata. Motivated by this, we analyze the computational capability of SPTO cluster phases on all vertex-translative 2D Archimedean lattices. There are four subsystem symmetries here called ribbon, cone, fractal, and 1-form symmetries, and the former three are fundamentally in one-to-one correspondence with three classes of Clifford quantum cellular automata. We conclude that nine out of the eleven Archimedean lattices support universal cluster phases protected by one of the former three symmetries, while the remaining lattices possess 1-form symmetry and have a different capability related to error correction. |
Monday, March 2, 2020 10:00AM - 10:12AM |
A07.00011: Parafermions and Z3 Charge-Flux attachment Peng Rao, Vijay Shenoy, Inti Sodemann A recent construction (Ann. Phys. 393, 234 (2018)) has introduced an interesting route to bosonization of fermions in two spatial dimensions by implementing a precise lattice version of flux-charge binding. The idea is to modify Kitaev's Toric code so that the electric charge (e) and magnetic flux (m) are always created in a tight ``dipolar" pair ε (=e x m) which is a fermion, providing a way to represent any local fermionic Hamiltonian as a local Hamiltonian of spins. We discuss an extension of these ideas to the case of a ZN toric which allows a bosonization of anyons with more general statitistical angles. We have focused particularly in the case of N=3. We wil prove that ground states in the torus in this case are at least three-fold degenerate, and, discuss a model featuring a topological phase transition between a 3-fold degenerate state and a 9-fold degenerate ground state featuring parafermionic excitations. |
Monday, March 2, 2020 10:12AM - 10:48AM |
A07.00012: Fun with fractons Invited Speaker: Dominic Williamson Interest in fracton topological order has grown explosively over the past several years, leading to a plethora of models that exhibit exotic topological physics tied to mobility constrained superselection sectors. At the same time a classification of even the simplest class of stabilizer fracton Hamiltonians remains elusive. I will describe some recent efforts to tame the vast array of models with the goal of a systematic construction and classification of all topological phases of matter in three spatial dimensions. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700