There are no clean samples in nature. Therefore, can one meaningfully quantify the effects of disorder on the entanglement structure of quantum states? In this talk, we investigate the entanglement structure of Tomonaga-Luttinger liquids (TLL) and random singlet (RS) states in an antiferromagnetically interacting Heisenberg spin chain. We make use of entanglement witness based measures like concurrence, tangle and quantum Fisher information (QFI), for this task, which can be related to experimentally accessible observables like spin correlations. Using quantum Fisher information (QFI), we demonstrate that both TLL and RS states exhibit multipartite entanglement. This result for the RS state, we attribute to the localization of multipartite entanglement below the crossover length. Additionally, we show that the order of disorder average matters for measures like concurrence and tangle, and this can lead to false inferences when ruling out RS states. Finally, we show that the low-temperature behavior of these witnesses can be utilized to characterize the effects of disorder. From the low-temperature behavior of concurrence, we extract the central charge information for the TLL state and conjecture this could be done for the RS state as well. Furthermore, using the equal-time structure factor as a multipartite entanglement witness, we demonstrate a distinct growth in multipartite entanglement in the two states.

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