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<h1>Introduction</h1>
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<h1>Introduction</h1>
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This code is based on the method described in the supplementary information of [this paper](https://arxiv.org/abs/2010.12965). It can be used to compute the time-evolution of a given inital state of spinful fermions in a 1D lattice under the Fermi-Hubbard Hamiltonian. The script 'Exact_Diagonalization.py' consists of the actual time evolution function. The script 'run_this_script.py' consists of all the parameters of the Hamiltonian and the initial state. Typically, one needs to edit only the latter script. The parameters are divided into two sections.
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This code is based on the method described in the supplementary information of [this paper](https://arxiv.org/abs/2010.12965). It can be used to compute the time-evolution of a given initial state of spinful fermions in a 1D lattice under the Fermi-Hubbard Hamiltonian. The script 'Exact_Diagonalization.py' consists of the actual time evolution function. The script 'run_this_script.py' consists of all the parameters of the Hamiltonian and the initial state. Typically, one needs to edit only the latter script. The parameters are divided into two sections.
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<h1>Section 1: Hamiltonian</h1>
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<h1>Section 1: Hamiltonian</h1>
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... | @@ -20,9 +20,11 @@ Below is a decription of the variables that appear in secion 1 of the script 'ru |
... | @@ -20,9 +20,11 @@ Below is a decription of the variables that appear in secion 1 of the script 'ru |
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7. U is as in the Hamiltonian.
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7. U is as in the Hamiltonian.
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8. ti is the initial time in milliseconds.
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8. ti is the initial time in milliseconds.
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9. tf is the final time in milliseconds
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9. tf is the final time in milliseconds
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10. n is the number of samples desired per millisecond.
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10. n is the number of samples desired per millisecond. Total number of samples is m= int(n*(tf-ti)) +1.
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11. alpha = <a href="https://www.codecogs.com/eqnedit.php?latex=\alpha" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\alpha" title="\alpha" /></a> in the Hamiltonian above.
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11. alpha = <a href="https://www.codecogs.com/eqnedit.php?latex=\alpha" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\alpha" title="\alpha" /></a> in the Hamiltonian above.
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<h1>Section 2: System size and initial state</h1>
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<h1>Section 2: System size and initial state</h1>
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The varaibles that appear in this section are described below.
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The varaibles that appear in this section are described below.
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... | @@ -30,6 +32,15 @@ The varaibles that appear in this section are described below. |
... | @@ -30,6 +32,15 @@ The varaibles that appear in this section are described below. |
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2. up_atm = an ordered array of integers less than L indicating the sites occupied by a spin up atom in the initial state.
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2. up_atm = an ordered array of integers less than L indicating the sites occupied by a spin up atom in the initial state.
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3. dn_atm = an ordered array of integers less than L indicating the sites occupied by a spin down atom in the initial state.
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3. dn_atm = an ordered array of integers less than L indicating the sites occupied by a spin down atom in the initial state.
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<h1>Section 3: Time evolution</h1>
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The time evolution produces three arrays.
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1. T = a 1D array of size m+1 consisting of points in time between ti and tf.
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2. NEUP= a 1D array of size m+1 consisting of the total spin-up occupancy of even sites at each of the m+1 points in time.
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3. NOUP= a 1D array of size m+1 consisting of the total spin-down occupancy of even sites at each of the m+1 points in time.
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The spin resolved even-odd imbalance can be computed as shown in the script.
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<h1>Example</h1>
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<h1>Example</h1>
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We consider L=21 sites and an initial state with
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We consider L=21 sites and an initial state with
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... | @@ -38,6 +49,6 @@ up_atm=[1, 5, 9, 13, 17] and |
... | @@ -38,6 +49,6 @@ up_atm=[1, 5, 9, 13, 17] and |
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dn_atm=[3, 7, 11, 15, 19]
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dn_atm=[3, 7, 11, 15, 19]
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We compute its time evolution under the stark Hamiltonian with <a href="https://www.codecogs.com/eqnedit.php?latex=\Delta&space;=&space;3J" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\Delta&space;=&space;3J" title="\Delta = 3J" /></a> and U=5J.
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We compute its time evolution under the stark Hamiltonian with <a href="https://www.codecogs.com/eqnedit.php?latex=\Delta&space;=&space;3J" target="_blank"><img src="https://latex.codecogs.com/gif.latex?\Delta&space;=&space;3J" title="\Delta = 3J" /></a> and U=5J. We show the even-odd imbalance of the spin up atoms from this computation below:
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\ No newline at end of file |