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Topologically Robust Bulk State In Non-Hermitian Acoustic System, Jannatul Ferdous

Theses and Dissertations

A closed system associated with Hermitian Hamiltonian allows real eigenvalues. However, the behavior and dynamics an open system (with gain and loss) will be addressed through the Non-Hermitian Hamiltonian. Though a non-Hermitian operator can allow only imaginary eigenvalues, if the Hamiltonian of a non-Hermitian operator obey the combined parity time (PT)-reversal symmetry it exhibits the real eigenvalues or energy spectrum. That is where the topology comes into account. If we add gain, loss or disorder in the system in such a way that the topology of the system does not change and keeping the …