I am trying to calculate the periodic dynamics of many-body systems (spin-1/2 XY) Hamiltonian, where,
H1=N−1∑i=1(σxiσxi+1+σyiσyi+1)+∑ihiσz
and
H2=∑ihiσz
where, hi is the disorder field and σ's are the Pauli spin-1/2 matrices. The dynamics take as
H(t)={H1if 0<T/2H2if T/2<t<T.
Here T is the time-period of the dynamics. The Floquet operator of evolution is given by
UF=e−iH2T/2e−iH1T/2.
The Above Hamiltonian can be written as the fermionic operators c†(c) where c†(c) are fermionic creation (annihilation) operator as
H(t)=∑mnC†mMmn(t)Cn
where C†=[c†c].
The basis state is given by
c†i1c†i2…c†iN|0⟩.
Where i1,i2,…,iN are set of integers such that 1≤i1,i2,…,iN≤N.
The time evolved state is given by
|ψ(t)⟩=e−iC†MCTc†i1c†i2…c†iN|0⟩
My aim is to calculate the average enegrgy e(T)=12⟨Ψ(t)|(H1+H2)|Ψ(t)⟩.From the Hamiltonian, M can be obtained. How to understand the basis state and how to do numerical with the state c†i1c†i2…c†iN|0⟩?