Time: 10:00-11:30  (Beijing time)Thursday, 2025/10/09 (October 9)
Location: Room 401, Building 7, UCAS Zhong-Guan-Cun Campus

Speaker: Robert de Mello Koch (Huzhou University)



Abstract:

This talk shows how entanglement can be organized and quantified through local unitary (LU) invariance. For two- and three-qubit systems, the LU perspective cleanly stratifies the state space into LU-inequivalent classes and yields transparent parameter counts for the corresponding families of entanglement types. I will also outline an algebraic invariant-theoretic approach—leveraging the Hochster–Roberts theorem and the Hironaka decomposition—to construct and interpret polynomial LU invariants. These tools provide finite generating sets and a primary/secondary decomposition that make the geometry of LU orbits explicit. Using this framework, the standard results for two and three qubits are recovered efficiently, clarifying both the minimal sets of invariants and the number of independent parameters needed to distinguish entanglement classes. The methods extend naturally to higher-qubit scenarios and suggest systematic routes for computing invariants beyond three qubits.


Link for Zoom meeting:

https://us06web.zoom.us/j/85715129440?pwd=QlJJRFBWWFRLMkxCVmcxZ1RKdlRxQT09

Meeting ID: 857 1512 9440
Passcode: 501105