http://192.168.1.40:8080/xmlui/handle/123456789/1116 Sun, 31 May 2026 10:36:31 GMT 2026-05-31T10:36:31Z http://192.168.1.40:80/xmlui/bitstream/id/f401bb05-08f6-448a-b0a7-7799736f6afa/som.jpg http://192.168.1.40:8080/xmlui/handle/123456789/1116 http://192.168.1.40:8080/xmlui/handle/123456789/1663 Entanglement cost of nonlocal measurements Bandyopadhyay, Somshubhro; Brassard, G.; Kimmel, S.; Wootters, W. K. For certain joint measurements on a pair of spatially separated particles, we ask how much entanglement is needed to carry out the measurement exactly. For a class of orthogonal measurements on two qubits with partially entangled eigenstates, we present upper and lower bounds on the entanglement cost. The upper bound is based on a recent result by Berry [Phys. Rev. A 75, 032349 (2007)]. The lower bound, based on the entanglement production capacity of the measurement, implies that for almost all measurements in the class we consider, the entanglement required to perform the measurement is strictly greater than the average entanglement of its eigenstates. On the other hand, we show that for any complete measurement in d X d dimensions that is invariant under all local generalized Pauli operations, the cost of the measurement is exactly equal to the average entanglement of the states associated with the outcomes. DOI: 10.1103/PhysRevA.80.012313 Wed, 01 Jul 2009 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1663 2009-07-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/1661 Entanglement and perfect discrimination of a class of multiqubit states by local operations and classical communication Bandyopadhyay, Somshubhro It is shown that while entanglement ensures difficulty in discriminating a set of mutually orthogonal states perfectly by local operations and classical communication (LOCC), entanglement content does not. In particular, for a class of entangled multiqubit states, the maximum number of perfectly LOCC distinguishable orthogonal states is shown to be independent of the average entanglement of the states, and the spatial configuration with respect to which LOCC operations may be carried out. It is also pointed out that for this class, the makeup of an ensemble, that is whether it consists only of entangled states or not, determines the maximum number of perfectly distinguishable states. DOI: 10.1103/PhysRevA.81.022327 Mon, 01 Feb 2010 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1661 2010-02-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/1291 Entanglement cost of two-qubit orthogonal measurements Bandyopadhyay, Somshubhro; Rahaman, Ramij; Wootters, William K. The ‘entanglement cost’ of a bipartite measurement is the amount of shared entanglement two participants need to use up in order to carry out the given measurement by means of local operations and classical communication. We numerically investigate the entanglement cost of generic orthogonal measurements on two qubits. Our results strongly suggest that for almost all measurements of this kind, the entanglement cost is strictly greater than the average entanglement of the eigenstates associated with the measurements, implying that the nonseparability of a two-qubit orthogonal measurement is generically distinct from the nonseparability of its eigenstates DOI: 10.1088/1751-8113/43/45/455303 Fri, 12 Nov 2010 00:00:00 GMT http://192.168.1.40:8080/xmlui/handle/123456789/1291 2010-11-12T00:00:00Z