Leggett-Garg Inequalities for Squeezed States
  Temporal Bell inequalities, or Leggett-Garg Inequalities (LGI), are studied
for continuous-variable systems placed in a squeezed state. The importance of
those systems lies in their broad applicability which allows the description of
many different physical settings in various branches of physics, ranging from
cosmology to condensed matter physics and from optics to quantum information
theory. LGI violations are explored and systematically mapped in squeezing
parameter space. Configurations for which LGI violation occurs are found but it
is shown that no violation can be obtained if all squeezing angles vanish,
contrary to what happens for the spatial Bell inequalities. We also assess the
effect of decoherence on the detectability of such violations. Our study opens
up the possibility of new experimental designs for the observation of LGI
violation.
