IFIMAC+ICMM Joint Seminar Series focuses on cutting-edge research on condensed matter physics, bringing speakers from all over the world to our Cantoblanco Campus. All talks are streamed online. Some of them will be celebrated on campus and onsite participation will also be possible. You need to subscribe to our mailing list at the link provided below to get the links to the seminar room. https://listas-correo.uam.es/sympa/subscribe/seminarios-ifimac-icmm-l

Simulation of topological phases in quantum dot arrays

Gloria Platero, Instituto de Ciencia de Materiales de Madrid ICMM-CSIC (Spain)

February 17th (Thursday), 2022, 12:00 CET. Hybrid on-line, onsite at ICMM

The fabrication and control of long semiconductor quantum dot arrays [1] open the possibility to use these systems for transferring quantum information between distant sites. Interestingly, it also opens the possibility of simulating, in quantum dot arrays, complex hamiltonians as 1D topological insulators. An example of them is the Su-Schrieffer-Hegger (SSH) model, a chain of dimers, which presents chiral symmetry and bond ordering of nearest-neighbor couplings and displays two topological phases. In a finite chain, the presence of protected edge states, allows to transfer electrons between edges, and therefore their implementation is promising for quantum information transfer. However, it does not account for long range hopping which should occur in real systems and which can destroy the topological properties and the edge states formation [2]. In this presentation I will show that, by applying an ac-driving protocol, all hopping amplitudes can be modified at will, imprinting bond-order and effectively producing structures such as dimers chains. Importantly, our protocol allows for the simultaneous suppression of all the undesired long-range hopping processes, enhancement of the necessary ones, and the appearance of new topological phases with increasing number of edge states. I will discuss the dynamics of two interacting electrons in a 12-QD array with different number of edge states. The correlated dynamics, which can be experimentally detected with QDs charge detectors, allows to discriminate between different topological phases and importantly, it opens a new avenue for quantum state transfer protocols [3].

[1] D.M. Zajac et al., Phys. Rev. App., 6, 054013 (2016),

[2] B. Pérez-González et al., Phys Rev. B, 99, 035146 (2019)

[3] B. Pérez-González et al., Phys. Rev. Lett., 123, 126401 (2019)