quantumzero/dynamics.py at main · yutuer21/quantumzero · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
"""
Created on Fri Oct 25 14:46:36 2019

@author: yuqinchen
"""

import numpy as np
from qutip import *
from numpy import *


class SatSearchEfficient():
    def __init__(self, n_qubit, T, Mcut,HB,HP,psi0,psif):
        self.n_qubit = n_qubit
        self.N = 2**self.n_qubit
        self.T = T
        self.Mcut = Mcut

        self.psi0 =psi0
        self.psif =psif

        self.H1=Qobj(HB)
        self.H2=Qobj(HP)


    def H1_coef(self, t, args):
        s = t/self.T
        j = 1
        for b in args:
            s += args[b] * np.sin(j*np.pi*t/self.T)
            j += 1
        return 1-s

    def H2_coef(self, t, args):
        s = t/self.T
        j = 1
        for b in args:
            s += args[b] * np.sin(j*np.pi*t/self.T)
            j += 1
        return s

    def evolution(self, bstate):
        """
        bstate: 1D array

        Return energy expectation and fidelity
        """
        args = {}
        for i, b in enumerate(list(bstate)):
            args['b{}'.format(i+1)] = b


        dt=0.5
        NL=self.T/dt


        t = np.linspace(dt, self.T-dt, int(NL))

        H = [[self.H1, self.H1_coef], [self.H2, self.H2_coef]]
        output = mesolve(H, self.psi0, t, args=args)


        states = output.states[-1]

        c= (self.psif.dag()) * states    ####overlap
        fidelity=np.abs(c[0,0])**2

        x=states.dag()*self.H2*states      ###energy
        energy=x[0,0]


        return energy, fidelity


    def fidelity(self, args):
        H = [[self.H1, self.H1_coef], [self.H2, self.H2_coef]]
        t = np.linspace(0, self.T, 100)
        output = mesolve(H, self.psi0, t, e_ops=self.obs, args=args)
        fidelity = output.expect[0][-1]
        return fidelity