Using Jordan-Winger transformation and finite Fourier transformation,the Hamiltonian of XX chain canbe transformed to the diagonal form.If the total qubits number N = odd,the internal energy U,and correlation function...Using Jordan-Winger transformation and finite Fourier transformation,the Hamiltonian of XX chain canbe transformed to the diagonal form.If the total qubits number N = odd,the internal energy U,and correlation functionG_(zz) in thermal equilibrium can be calculated.Then the pairwise concurrence and the critical value β_(cr) can be calculated.For N≥5 XX chains,there are pairwise concurrences in thermal equilibrium for antiferromagnetic and ferromagneticeases when β>β_(cr).展开更多
文摘Using Jordan-Winger transformation and finite Fourier transformation,the Hamiltonian of XX chain canbe transformed to the diagonal form.If the total qubits number N = odd,the internal energy U,and correlation functionG_(zz) in thermal equilibrium can be calculated.Then the pairwise concurrence and the critical value β_(cr) can be calculated.For N≥5 XX chains,there are pairwise concurrences in thermal equilibrium for antiferromagnetic and ferromagneticeases when β>β_(cr).
