Formation probabilities and statistics of observables as defect problems in free fermions and quantum spin chains

  title={Formation probabilities and statistics of observables as defect problems in free fermions and quantum spin chains},
  author={M N Najafi and Morteza Rajabpour},
  journal={Physical Review B},
We show that the computation of formation probabilities (FP) in the configuration basis and the full counting statistics (FCS) of observables in the quadratic fermionic Hamiltonians are equivalent to the calculation of emptiness formation probability (EFP) in the Hamiltonian with a defect. In particular, we first show that the FP of finding a particular configuration in the ground state is equivalent to the EFP of the ground state of the quadratic Hamiltonian with a defect. Then, we show that… 

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