PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA (CCEN - PPGF)
CENTRO DE CIÊNCIAS EXATAS E DA NATUREZA (CCEN)
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Banca de DEFESA: RAFAEL ALVES BATISTA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: RAFAEL ALVES BATISTA
DATA: 18/07/2023
HORA: 09:00
LOCAL: https://meet.google.com/bvi-wdhv-bvb
TÍTULO: UNVEILING THE UNIVERSAL CLASS
CATEGORIZATION OF ALTLAND-ZIRNBAUER IN
MESOSCOPIC SYSTEMS: PROBING ENTANGLEMENT
AND CONDUCTANCE FLUCTUATIONS
PALAVRAS-CHAVES: Tenfold way; Altland-Zirnbauer classification; Random-Matrix Theory; Conduc-
tance Peaks; Shot Noise Power; Quantum Entanglement; Bells inequality.
PÁGINAS: 192
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO: In this thesis, we present the ten classes of Altland-Zirnbauer symmetry and how they are used
to describe universal quantum transport in mesoscopic systems, particularly chaotic quantum
dots. We perform numerical simulations using Random Matrix Theory (RMT) to explore trans-
port properties such as conductance and shot noise power, as well as entanglement quantifiers
including concurrence, entanglement formation, and Bell inequality. We begin by introducing
the description of our system, the chaotic quantum billiard. Then, we derive the Mahaux-
Weidenmüller formula for the scattering matrix, and consequently, the conductance and shot
noise power. We then present the possible fundamental symmetries present in mesoscopic sys-
tems, such as time-reversal symmetry, spin rotation, chirality, and particle-hole symmetry. In
this way, we explore how these symmetries impose constraints on the Hamiltonian and, con-
sequently, the scattering matrix. Finally, we present numerical results showing the influence
of these fundamental symmetries on transport and entanglement properties. We provide a sta-
tistical analysis of the conductance and shot noise power for Schrödinger, Dirac, and Andreev
billiards. Specifically, we observe that chiral and particle-hole symmetries play a role in the
universal conductance fluctuations. In addition to transport properties, we perform numeri-
cal simulations of quantum entanglement in chaotic quantum billiards. We observe violations
of the Bell inequality for all billiards and analyze their dependencies on the number of reso-
nances and barrier transparency. We demonstrate that it is easier to violate the Bell inequality
in chiral/sublattice and particle-hole degrees of freedom than in orbital degrees of freedom.
Moreover, our results exhibit a unique and peculiar behavior: the realization of entanglement
in the Andreev billiard always results in the production of Bell pairs in the single-channel limit,
regardless of the presence of time-reversal symmetry and tunneling rates. The entangled pairs
are formed by Majorana modes in an interface of different topological phases and may serve as
a useful tool for entanglement generation and control, as well as quantum computing
MEMBROS DA BANCA:
Presidente - 1572287 - JORGE GABRIEL GOMES DE SOUZA RAMOS
Interno - 6332381 - DIONISIO BAZEIA FILHO
Interno - 321413 - JOAO ANTONIO PLASCAK
Externo à Instituição - CAIO HENRIQUE LEWENKOPF
Externo à Instituição - TARCÍSIO MARCIANO DA ROCHA FILHO