@article{ISI:000312697500006,
 abstract = {Recently it has been shown that the fidelity of the ground state of a
quantum many-body system can be used todetect its quantum critical
points (QCPs). If g denotes the parameter in the Hamiltonian with
respect to which the fidelity is computed, we find that for
one-dimensional models with large but finite size, the fidelity
susceptibility chi(F) can detect a QCP provided that the correlation
length exponent satisfies nu < 2. We then show that chi(F) can be used
to locate a QCP even if nu >= 2 if we introduce boundary conditions
labeled by a twist angle N theta, where N is the system size. If the QCP
lies at g = 0, we find that if N is kept constant, chi(F) has a scaling
form given by chi(F) similar to theta(-2/nu) f (g/theta(1/nu)) if theta
<< 2 pi/N. We illustrate this both in a tight-binding model of fermions
with a spatially varying chemical potential with amplitude h and period
2q in which nu = q, and in a XY spin-1/2 chain in which nu = 2. Finally
we show that when q is very large, the model has two additional QCPs at
h = +/- 2 which cannot be detected by studying the energy spectrum but
are clearly detected by chi(F). The peak value and width of chi(F) seem
to scale as nontrivial powers of q at these QCPs. We argue that these
QCPs mark a transition between extended and localized states at the
Fermi energy. DOI: 10.1103/PhysRevB.86.245424},
 article-number = {245424},
 author = {Thakurathi, Manisha and Sen, Diptiman and Dutta, Amit},
 doi = {10.1103/PhysRevB.86.245424},
 eissn = {2469-9969},
 issn = {2469-9950},
 journal = {PHYSICAL REVIEW B},
 month = {DEC 21},
 number = {24},
 times-cited = {7},
 title = {Fidelity susceptibility of one-dimensional models with twisted boundary
conditions},
 unique-id = {ISI:000312697500006},
 volume = {86},
 year = {2012}
}