  We obtain the left-right entanglement entropy (LREE) for a D$p$-brane with
tangential motion in the presence of a $U(1)$ gauge potential, the Kalb-Ramond
field and an open string tachyon field. Thus, at first we extract the R\'{e}nyi
entropy and then by taking a special limit of it we acquire the entanglement
entropy. We shall investigate the behavior of the LREE under the tachyon
condensation phenomenon. We observe that the deformation of the LREE, through
this process, reveals the collapse of the brane. Besides, we examine the second
law of thermodynamics for the LREE under tachyon condensation, and we extract
the imposed constraints. Note that our calculations will be in the context of
the type IIA/IIB superstring theories.
