Miniworkshop on Quantum Information and CFTs

Contribution List

1. Half a qubit: an algebraic fractionalization, Po-Yao Chang

18/11/2026, 09:30

Fractionalizing a quantum two-level system is usually associated with encodings based on pairs of Majorana fermions---an operational fractionalization. We show an alternative algebraic fractionalization by embedding Székely's classical ``half-coin'' into a non-Hermitian Krein space. The coefficients of $(q+pz)^{1/2}$ define a signed sequence and a normalized, non-Hermitian biorthogonal...

5. Beyond Boson Sampling: From Higher Spins to Open Quantum Dynamics, En-Jui Kuo

18/11/2026, 10:15

Boson sampling provides a promising route toward demonstrating quantum computational advantage, but its experimental implementation remains challenging due to demanding physical resource requirements. In this talk, I will discuss two approaches to extending boson sampling beyond idealized bosonic systems. First, I will introduce a higher-spin sampling framework in which finite-dimensional spin...

2. Entanglement in $c=-2$ Logarithmic Conformal Field Theory, Kuang-Hung Chou

18/11/2026, 11:15

The replica trick is widely used to calculate entanglement and R\'enyi entropies in conformal field theory, but its application to logarithmic and non-unitary theories is less understood. We study this problem in $c=-2$ logarithmic CFTs, using symplectic fermions and the continuum theory of the non-Hermitian SSH model as complementary realizations. We find an odd--even splitting of the R\'enyi...

3. Tensor network, renormalization group, and conformal field theory

Prof. Pochung Chen (NTHU)

18/11/2026, 13:30

In this talk, I will discuss the deep connection between tensor network renormalization method and renormalization group concept. I will explain how to use this connection to extract the critical point and critical exponents. After that I will further extend the connection to conformal field theory. I will explain how to extract conformal data, including central charge, scaling dimension,...

6. Exact organization of density matrices and entanglement structure in the Kitaev spin liquid, Chen-Chih Wang

18/11/2026, 14:30

We give an exact form of the density matrix for the spin-1/2 Kitaev spin liquid, expressed in terms of spin operators, and study the entanglement structure of the Kitaev spin liquid within the spin framework. We show that the density matrix is naturally organized by equivalence classes of string operators associated with the underlying gauge structure of the model. Using the explicit form of...