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1 vote
0 answers
77 views

Exact ground state degeneracy for quantum spin system with non commuting terms and its quantum phase transition?

Let's say I have a 2D quantum spin model of N spin-1/2 particles, with two terms: $$ H = -J \sum_N \prod_{i \in G} \sigma^x_i - h \sum_N \prod_{i \in G'} \sigma^z_i $$ The first is a collection of ...
Kostas's user avatar
  • 29
5 votes
0 answers
474 views

1D transverse-field Ising model - what is the difference between its classical and quantum treatment?

The 1D transverse field Ising model: $$ H(\sigma)=-J\sum_{i\in Z} \sigma^x_i \sigma^x_{i+1} -h \sum_{i \in Z} \sigma^z_i$$ is usually solved in quantum way, but we can also solve it classically - ...
Jarek Duda's user avatar
3 votes
2 answers
652 views

Jordan-Wigner transformation for lattice models without $U(1)$ symmetry

The Jordan-Wigner transformation is a powerful approach to studying one-dimensional spin models. The following dictionary between spin operators and creation/annihilation operators for fermions allows ...
miggle's user avatar
  • 759
1 vote
1 answer
431 views

1D Ising Model with magnetic field on even sites: Transfer Matrices

I have been trying to work out a practice problem after reading about Transfer Matrices method for solving 1D Ising Model. Please, if you are able to, tell me whether the way I introduced transfer ...
Light's user avatar
  • 61
4 votes
2 answers
2k views

Kagome Lattice: Spin-orbit coupling Hamiltonian in tight-binding models

Consider spin-orbit coupling (of strength $\lambda_1$) on lattice, with the below Hamiltonian $$H = i \lambda_1 \sum_{<ij>} ~\frac{E_{ij} \times R_{ij}}{|E_{ij} \times R_{ij}|} \cdot \sigma ~...
Nigel1's user avatar
  • 359
1 vote
0 answers
223 views

How to find groundstate energy of a simple Hamiltonian at $N/L$-filling using Jordan-Wigner (JW) transformation?

$\underline{\textbf{Model:}}$ Let we have the $t-V$ model for spinless fermions on a 1D lattice, which is defined in second quantization operators as follows: $$H_1 = -t\sum_i \big(c_i^\dagger c_{i+...
Luqman Saleem's user avatar
0 votes
0 answers
117 views

References or resource recommendation for mapping of 1D spinless Hubbard model into XXZ Heisenberg model

I read from somewhere that 1D spinless Hubbard model can be mapped onto XXZ Heisenberg model but I don't remember from where did I read this sentence. I tried googling it but couldn't find any thing ...
Luqman Saleem's user avatar
16 votes
2 answers
2k views

Interpretation of the 1D transverve field Ising model vacuum state in a spin-language

The 1D transverse field Ising model, \begin{equation} H=-J\sum_{i}\sigma_i^z\sigma_{i+1}^z-h\sum_{i}\sigma^x_i, \end{equation} can be solved via the Jordan-Wigner (JW) transformation (for further ...
VanillaSpinIce's user avatar