Identification of non-Fermi liquid fermionic self-energy from quantum Monte Carlo data

Fermionic R-Operator and Algebraic Structure of 1D Hubbard Model: Its application to quantum transfer matrix

The algebraic structure of the 1D Hubbard model is studied by means of the fermionic R-operator approach. This approach treats the fermion models directly in the framework of the quantum inverse scattering method. Compared with the graded approach, this approach has several advantages. First, the global properties of the Hamiltonian are naturally reflected in the algebraic properties of the fermionic R-operator. We want to note that this operator is a local operator acting on fermion Fock spaces. In particular, SO(4) symmetry and the invariance under the partial particle hole transformation ar…

A theory of 2+1D fermionic topological orders and fermionic/bosonic topological orders with symmetries

We propose that, up to invertible topological orders, 2+1D fermionic topological orders without symmetry and 2+1D fermionic/bosonic topological orders with symmetry $G$ are classified by non-degenerate unitary braided fusion categories (UBFC) over a symmetric fusion category (SFC); the SFC describes a fermionic product state without symmetry or a fermionic/bosonic product state with symmetry $G$, and the UBFC has a modular extension. We developed a simplified theory of non-degenerate UBFC over a SFC based on the fusion coefficients $N^{ij}_k$ and spins $s_i$. This allows us to obtain a list th…

Semi-fermionic approach for quantum spin systems

We present a general derivation of semi-fermionic representation for generators of SU(N) group as a bilinear combination of Fermi operators. The constraints are fulfilled by means of imaginary Lagrange multipliers. The important case of SU(2) group is discussed. We demonstrate how the idea of semi-fermionic representation might be extended to the groups possessing dynamic symmetries. As an example, SO(4) group is considered. We illustrate the application of semi-fermionic representations for various problems of strongly correlated physics.

Contraction of fermionic operator circuits and the simulation of strongly correlated fermions

A fermionic operator circuit is a product of fermionic operators of usually different and partially overlapping support. Further elements of fermionic operator circuits (FOCs) are partial traces and partial projections. The presented framework allows for the introduction of fermionic versions of known qudit operator circuits (QUOC), important for the simulation of strongly correlated d-dimensional systems: The multiscale entanglement renormalization ansatz (MERA), tree tensor networks (TTN), projected entangled pair states (PEPS), or their infinite-size versions (iPEPS etc.). After the definit…

无平凡低能态的费米子哈密顿量

Fermionic Hamiltonians without trivial low-energy states

本文构造了无低能平凡态的局域费米子哈密顿量，定义了费米子NLTS定理，并探讨了量子PCP类的费米子类比及其与量子比特版本的关系。

量子自旋与费米子Casimir效应之间的Jordan-Wigner映射

Jordan-Wigner mapping between quantum-spin and fermionic Casimir effects

本文通过Jordan-Wigner变换揭示量子自旋系统与费米子Casimir效应之间的联系，展示了有限尺寸修正与费米子Casimir效应的对应关系，并发现多种Casimir现象。