ترغب بنشر مسار تعليمي؟ اضغط هنا

Topologically protected braiding in a single wire using Floquet Majorana modes

72   0   0.0 ( 0 )
 نشر من قبل Bela Bauer
 تاريخ النشر 2018
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Majorana zero modes are a promising platform for topologically protected quantum information processing. Their non-Abelian nature, which is key for performing quantum gates, is most prominently exhibited through braiding. While originally formulated for two-dimensional (2d) systems, it has been shown that braiding can also be realized using one-dimensional (1d) wires by forming an essentially two-dimensional network. Here, we show that in driven systems far from equilibrium, one can do away with the second spatial dimension altogether by instead using quasienergy as the second dimension. To realize this, we use a Floquet topological superconductor which can exhibit Majorana modes at two special eigenvalues of the evolution operator, 0 and pi, and thus can realize four Majorana modes in a single, driven quantum wire. We describe and numerically evaluate a protocol that realizes a topologically protected exchange of two Majorana zero modes in a single wire by adiabatically modulating the Floquet drive and using the pi modes as auxiliary degrees of freedom.



قيم البحث

اقرأ أيضاً

Detection and manipulation of excitations with non-Abelian statistics, such as Majorana fermions, are essential for creating topological quantum computers. To this end, we show the connection between the existence of such localized particles and the phenomenon of unitary subharmonic response (SR) in periodically driven systems. In particular, starting from highly nonequilibrium initial states, the unpaired Majorana modes exhibit spin oscillations with twice the driving period, are localized, and can have exponentially long lifetimes in clean systems. While the lifetime of SR is limited in translationally invariant systems, we show that disorder can be engineered to stabilize the subharmonic response of Majorana modes. A viable observation of this phenomenon can be achieved using modern multiqubit hardware, such as superconducting circuits and cold atomic systems.
We propose a topological plasmonic crystal structure composed of an array of parallel nanowires with unequal spacing. In the paraxial approximation, the Helmholtz equation that describes the propagation of light along the nanowires maps onto the Schr {o}dinger equation of the Su-Schrieffer-Heeger (SSH) model. Using full three-dimensional finite difference time domain solution of the Maxwell equations we demonstrate the existence of topological defect modes, with sub-wavelength localization, bound to kinks of the plasmonic crystal. Furthermore, we show that by manipulating kinks we can construct spatial mode filters, that couple bulk modes to topological defect modes, and topological beam-splitters that couple two topological defect modes. Finally, we show that the structures are robust to fabrication errors with inverse length-scale smaller than the topological band gap.
79 - Christopher Sims 2020
The observation of wormholes has proven to be difficult in the field of astrophysics. However, with the discovery of novel topological quantum materials it is possible to observe astrophysical and particle physics effects in condensed matter physics. In this work, we propose that wormholes can exist in a type-III Weyl phase. In addition, these wormholes are topologically protected, making them feasible to create and measure in condensed matter systems. Finally, several systems and experiments are put forward to confirm the existence of a type-III Weyl phase.
90 - K. L. Zhang , Z. Song 2021
Edge states exhibit the nontrivial topology of energy band in the bulk. As localized states at boundaries, many-particle edge states may obey a special symmetry that is broken in the bulk. When local particle-particle interaction is induced, they may support a particular property. We consider an anisotropic two-dimensional Su-Schrieffer-Heeger Hubbard model and examine the appearance of $eta$-pairing edge states. In the absence of Hubbard interaction, the energy band is characterized by topologically invariant polarization in association with edge states. In the presence of on-site Hubbard interaction, $eta$-pairing edge states with an off-diagonal long-range order appear in the nontrivial topological phase, resulting in the condensation of pairs at the boundary. In addition, as Hamiltonian eigenstates, the edge states contain one paired component and one unpaired component. Neither affects the other; they act as two-fluid states. From numerical simulations of many-particle scattering processes, a clear manifestation and experimental detection scheme of topologically protected two-fluid edge states are provided.
We study Majorana zero modes properties in cylindrical cross-section semiconductor quantum wires based on the $k cdot p$ theory and a discretized lattice model. Within this model, the influence of disorder potentials in the wire and amplitude and pha se fluctuations of the superconducting order-parameter are discussed. We find that for typical wire geometries, pairing potentials, and spin-orbit coupling strengths, coupling between quasi-one-dimensional sub-bands is weak, low-energy quasiparticles near the Fermi energy are nearly completely spin-polarized, and the number of electrons in the active sub-bands of topological states is small.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا