@article {330, title = {Entanglement-fluctuation relation for bipartite pure states}, journal = {Phys. Rev. A}, volume = {94}, year = {2016}, pages = {022323}, abstract = {We identify subsystem fluctuations (variances) that measure entanglement in an arbitrary bipartite pure state. These fluctuations are of observables that generalize the notion of polarization to an arbitrary N-level subsystem. We express this polarization fluctuation in terms of subsystem purity and other entanglement measures. The derived entanglement-fluctuation relation is evaluated for the ground states of a one-dimensional free-fermion gas and the Affleck-Kennedy-Lieb-Tasaki spin chain. Our results provide a framework for experimentally measuring entanglement using Stern-Gerlach{\textendash}type state selectors.}, doi = {10.1103/PhysRevA.94.022323}, url = {http://link.aps.org/doi/10.1103/PhysRevA.94.022323}, author = {Aura Mae B Villaruel and Francis N. C. Paraan} } @conference {351, title = {Polarization fluctuation as an entanglement measure for N-level systems}, year = {2016}, month = {7{\textendash}8 Apr 2016}, pages = {127}, publisher = {1st International DOST-SEI ASTHRDP-NSC Scholars{\textquoteright} Conference}, address = {PICC, Pasay City}, abstract = {It is known that subsystem fluctuations are related to entanglement for any N-level system entangled with an environment. We define an observable wherein its fluctuations can be directly related to known measures such as the purity, R{\'e}nyi-2 entropy, and concurrence. This quantity, which we call the Schmidt polarization fluctuation shows an exact relationship between fluctuations and entanglement that is simple to construct and is model-independent. It can also be considered as a proper entanglement measure and is experimentally accessible.}, author = {Aura Mae B Villaruel and Francis N. C. Paraan} } @inproceedings {321, title = {Polarization fluctuation as an entanglement monotone for entangled two-level systems}, booktitle = {Proceedings of the AQIS Conference 2015}, year = {2015}, month = {24{\textendash}30 Aug 2015}, pages = {271-272}, address = {Korea Institute for Advanced Study, Seoul}, abstract = {In a pure system consisting of a two-level atom (qubit) entangled with an arbitrary environment, the polarization fluctuation about the Schmidt axis is shown to preserve majorization. This polarization fluctuation is additive over independent two-level systems and is proposed to be an experimentally accessible entanglement monotone for a generic gas of two-level atoms entangled with a common bath.}, url = {http://aqis-conf.org/2015/program/}, author = {Aura Mae B Villaruel and Francis N. C. Paraan} } @inproceedings {villaruel-spp-2015, title = {Polarization fluctuation can partially order entangled qubit states}, booktitle = {Proceedings of the 33rd Samahang Pisika ng Pilipinas Physics Congress}, year = {2015}, month = {3{\textendash}6 Jun 2015}, pages = {SPP-2015-3B-03}, address = {University of Northern Philippines, Vigan City}, abstract = {