Data: 17/07/2025 (quinta-feira)
Horário: 11:00 h
Local: Sala 528 da torre nova <<<<Atenção para o Local
Caros estudantes e docentes,
Na próxima semana teremos um seminário do grupo de matéria condensada.
Ele ocorrerá com a apresentação do Dr. Matheus de Sousa (Shanghai Jiao Tong University). O título e abstract seguem abaixo.
Tarik em nome da comissão organizadora.
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Título: Eigenparticle Picture and Absence of Superfluidity in Geometrically Frustrated Systems
Resumo: Geometric frustration is known to severely hinder kinetic processes in certain lattice geometries (e.g., kagome, pyrochlore), often producing flat bands in non-interacting systems. The effects of introducing interactions into such frustrated systems, however, remain highly controversial. Numerical studies of geometrically frustrated systems of hard-core bosons typically yield glassy or solid phases that exhibit only local many-body coherence, suggesting a continued suppression of quantum coherence. Despite this, the literature contains persistent claims of superfluidity, which implies coherent particle flow across the system. To resolve this apparent contradiction, we present an analytical proof that uses eigenparticle picture to show that, under general conditions such as low particle density or the absence of long-range correlations, density-density interactions do not enable long-range space-time propagation in these systems—let alone superfluidity. Instead, it reveals a new possibility of many-body localized (MBL) states which are robust to decoherence and manipulable using magnetic field or uniaxial pressure.
References:
1. Manipulable Compact Many-Body Localization and Absence of Superfluidity in Geometrically Frustrated Systems
Xinyao Zhang, Matheus S. M. de Sousa, Xinyi Li, Anthony Hegg, Wei Ku, arXiv:2408.03939
