All Questions
Tagged with spin-chains symmetry-breaking
11
questions
3
votes
1
answer
87
views
Can a $\mathbb{Z}_2 \times \mathbb{Z}_2$ symmetry generated by $\prod_{i} \sigma^x_i$ and $\prod_{i} \sigma^z_i$ be broken in a spin-$1/2$ chain?
I am interested in understanding patterns of spontaneous symmetry breaking in spin chains. I want to understand what happens when I have "competing" orders, like symmetry breaking orders ...
- 2,292
1
vote
0
answers
70
views
Emergent higher symmetry breaking without topological order?
In this paper prof. Wen states that (p.6)
a spontaneous higher symmetry broken state always corresponds to a topologically ordered state.
Are there examples of simple (or not) quantum spin models ...
- 29
2
votes
1
answer
573
views
$G$-injective MPS and symmetry-broken phases
First, a little bit of motivation. I was reading the paper "Matrix Product States and Projected Entangled Pair States" to try to learn more about MPS representations of symmetry broken ...
- 2,292
2
votes
1
answer
501
views
Long-range correlations in transverse field Ising model
The transverse field Ising model in 1+1d has two phases: a symmetric "disordered" phase and a symmetry-breaking "ordered" phase. Both of these phases have a finite excitation gap. ...
- 8,343
0
votes
0
answers
380
views
Magnetization ($z$-basis) of a 1D Transverse Ising Model
I'm trying to find the magnetization $\langle\sigma_{z} \rangle$ of a 1D transverse Ising chain and plot it as a function of the transverse field $\lambda$. More specifically, I want to plot this for ...
4
votes
2
answers
763
views
How can I simulate a ground state degenerate system numerically?
I'm using numerical method like DMRG to simulate ground state of correlated systems. But the degeneracy of the ground state has long bothered me:
When degeneracy exists the ground state isn't unique. ...
- 118
8
votes
0
answers
618
views
Mermin-Wagner and Heisenberg spin chains
The Hamiltonian for the spin 1/2 ferromagnetic Heisenberg spin chain is $H=-J\sum_i \vec \sigma_i \cdot \vec\sigma_{i+1}$ with $J>0$ and $\vec\sigma_i$ the Pauli matrices acting on ith lattice site....
- 8,815
3
votes
1
answer
917
views
Does one-dimensional ferromagnetic chain have long range order at zero tempreture?
In many text books on one dimensional quantum magnetic systems, it's said there is no orderd state for one dimensional magnetic systems. I understand that the one dimensional spin half ...
- 356
7
votes
1
answer
867
views
Goldstone mode as spin wave in 2D?
I'm trying to understand how Goldstone modes destroy long range order in 1D and 2D spin lattice.
I started with a spin chain, using 1D XY-model, which has continuous symmetry. $H=- \sum_{<i j>} ...
- 314
9
votes
3
answers
756
views
Naive questions on Goldstone modes and a possible duality relation?
For example, let's consider a 1D spin-1/2 ferromagnetic (FM) Heisenberg chain $H=-J\sum_{i=1}^{N}\mathbf{S}_i\cdot\mathbf{S}_{i+1}$ with periodic boundary conditions. Now we want to study its low ...
- 3,744
3
votes
1
answer
461
views
Spontaneous symmetry breaking in the quantum 1D XX model?
The ground states of the quantum 1D Ising and Heisenberg models exhibit spontaneous magnetization. Is this also true for the 1D XX model?
- 1,050