@article{kozlowski_quantum_2017, title = {Quantum {State} {Reduction} by {Matter}-{Phase}-{Related} {Measurements} in {Optical} {Lattices}}, volume = {7}, copyright = {2017 Nature Publishing Group}, issn = {2045-2322}, url = {https://www.nature.com/articles/srep42597}, doi = {10.1038/srep42597}, abstract = {A many-body atomic system coupled to quantized light is subject to weak measurement. Instead of coupling light to the on-site density, we consider the quantum backaction due to the measurement of matter-phase-related variables such as global phase coherence. We show how this unconventional approach opens up new opportunities to affect system evolution. We demonstrate how this can lead to a new class of final states different from those possible with dissipative state preparation or conventional projective measurements. These states are characterised by a combination of Hamiltonian and measurement properties thus extending the measurement postulate for the case of strong competition with the system’s own evolution.}, language = {en}, urldate = {2019-02-07}, journal = {Scientific Reports}, author = {Kozlowski, Wojciech and Caballero-Benitez, Santiago F. and Mekhov, Igor B.}, month = feb, year = {2017}, pages = {42597}, file = {Full Text PDF:/home/wojtek/Zotero/storage/JG32Q99Y/Kozlowski et al. - 2017 - Quantum State Reduction by Matter-Phase-Related Me.pdf:application/pdf;Snapshot:/home/wojtek/Zotero/storage/M69DXSEV/srep42597.html:text/html} } @article{mazzucchi_collective_2016, title = {Collective dynamics of multimode bosonic systems induced by weak quantum measurement}, volume = {18}, issn = {1367-2630}, url = {https://doi.org/10.1088%2F1367-2630%2F18%2F7%2F073017}, doi = {10.1088/1367-2630/18/7/073017}, language = {en}, number = {7}, urldate = {2019-02-07}, journal = {New Journal of Physics}, author = {Mazzucchi, Gabriel and Kozlowski, Wojciech and Caballero-Benitez, Santiago F. and Mekhov, Igor B.}, month = jul, year = {2016}, pages = {073017}, file = {IOP Full Text PDF:/home/wojtek/Zotero/storage/IP9P4EJZ/Mazzucchi et al. - 2016 - Collective dynamics of multimode bosonic systems i.pdf:application/pdf} } @article{kozlowski_non-hermitian_2016, title = {Non-{Hermitian} dynamics in the quantum {Zeno} limit}, volume = {94}, url = {https://link.aps.org/doi/10.1103/PhysRevA.94.012123}, doi = {10.1103/PhysRevA.94.012123}, abstract = {We show that weak measurement leads to unconventional quantum Zeno dynamics with Raman-like transitions via virtual states outside the Zeno subspace. We extend this concept into the realm of non-Hermitian dynamics by showing that the stochastic competition between measurement and a system's own dynamics can be described by a non-Hermitian Hamiltonian. We obtain a solution for ultracold bosons in a lattice and show that a dark state of tunneling is achieved as a steady state in which the observable's fluctuations are zero and tunneling is suppressed by destructive matter-wave interference.}, number = {1}, urldate = {2019-02-07}, journal = {Physical Review A}, author = {Kozlowski, W. and Caballero-Benitez, S. F. and Mekhov, I. B.}, month = jul, year = {2016}, pages = {012123}, file = {APS Snapshot:/home/wojtek/Zotero/storage/7VKZZQKP/PhysRevA.94.html:text/html;Full Text PDF:/home/wojtek/Zotero/storage/3Y8N66ZD/Kozlowski et al. - 2016 - Non-Hermitian dynamics in the quantum Zeno limit.pdf:application/pdf} } @article{elliott_probing_2015, title = {Probing and {Manipulating} {Fermionic} and {Bosonic} {Quantum} {Gases} with {Quantum} {Light}}, volume = {3}, copyright = {http://creativecommons.org/licenses/by/3.0/}, url = {https://www.mdpi.com/2218-2004/3/3/392}, doi = {10.3390/atoms3030392}, abstract = {We study the atom-light interaction in the fully quantum regime, with the focus on off-resonant light scattering into a cavity from ultracold atoms trapped in an optical lattice. The detection of photons allows the quantum nondemolition (QND) measurement of quantum correlations of the atomic ensemble, distinguishing between different quantum states. We analyse the entanglement between light and matter and show how it can be exploited for realising multimode macroscopic quantum superpositions, such as Schrödinger cat states, for both bosons and fermions. We provide examples utilising different measurement schemes and study their robustness to decoherence. Finally, we address the regime where the optical lattice potential is a quantum dynamical variable and is modified by the atomic state, leading to novel quantum phases and significantly altering the phase diagram of the atomic system.}, language = {en}, number = {3}, urldate = {2019-02-07}, journal = {Atoms}, author = {Elliott, Thomas J. and Mazzucchi, Gabriel and Kozlowski, Wojciech and Caballero-Benitez, Santiago F. and Mekhov, Igor B.}, month = sep, year = {2015}, keywords = {cavity QED, many-body quantum systems, quantum light-matter interactions, quantum nondemolition measurement}, pages = {392--406}, file = {Full Text PDF:/home/wojtek/Zotero/storage/3VNQ36WU/Elliott et al. - 2015 - Probing and Manipulating Fermionic and Bosonic Qua.pdf:application/pdf;Snapshot:/home/wojtek/Zotero/storage/BS9QK6BF/392.html:text/html} } @article{mazzucchi_quantum_2016, title = {Quantum measurement-induced dynamics of many-body ultracold bosonic and fermionic systems in optical lattices}, volume = {93}, url = {https://link.aps.org/doi/10.1103/PhysRevA.93.023632}, doi = {10.1103/PhysRevA.93.023632}, abstract = {Trapping ultracold atoms in optical lattices enabled numerous breakthroughs uniting several disciplines. Coupling these systems to quantized light leads to a plethora of new phenomena and has opened up a new field of study. Here we introduce an unusual additional source of competition in a many-body strongly correlated system: We prove that quantum backaction of global measurement is able to efficiently compete with intrinsic short-range dynamics of an atomic system. The competition becomes possible due to the ability to change the spatial profile of a global measurement at a microscopic scale comparable to the lattice period without the need of single site addressing. In coherence with a general physical concept, where new competitions typically lead to new phenomena, we demonstrate nontrivial dynamical effects such as large-scale multimode oscillations, long-range entanglement, and correlated tunneling, as well as selective suppression and enhancement of dynamical processes beyond the projective limit of the quantum Zeno effect. We demonstrate both the breakup and protection of strongly interacting fermion pairs by measurement. Such a quantum optical approach introduces into many-body physics novel processes, objects, and methods of quantum engineering, including the design of many-body entangled environments for open systems.}, number = {2}, urldate = {2019-02-07}, journal = {Physical Review A}, author = {Mazzucchi, Gabriel and Kozlowski, Wojciech and Caballero-Benitez, Santiago F. and Elliott, Thomas J. and Mekhov, Igor B.}, month = feb, year = {2016}, pages = {023632}, file = {APS Snapshot:/home/wojtek/Zotero/storage/ZRTPQGVA/PhysRevA.93.html:text/html;Full Text PDF:/home/wojtek/Zotero/storage/V2G8VPX6/Mazzucchi et al. - 2016 - Quantum measurement-induced dynamics of many-body .pdf:application/pdf} } @article{elliott_multipartite_2015, title = {Multipartite {Entangled} {Spatial} {Modes} of {Ultracold} {Atoms} {Generated} and {Controlled} by {Quantum} {Measurement}}, volume = {114}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.114.113604}, doi = {10.1103/PhysRevLett.114.113604}, abstract = {We show that the effect of measurement backaction results in the generation of multiple many-body spatial modes of ultracold atoms trapped in an optical lattice, when scattered light is detected. The multipartite mode entanglement properties and their nontrivial spatial overlap can be varied by tuning the optical geometry in a single setup. This can be used to engineer quantum states and dynamics of matter fields. We provide examples of multimode generalizations of parametric down-conversion, Dicke, and other states; investigate the entanglement properties of such states; and show how they can be transformed into a class of generalized squeezed states. Furthermore, we propose how these modes can be used to detect and measure entanglement in quantum gases.}, number = {11}, urldate = {2019-02-07}, journal = {Physical Review Letters}, author = {Elliott, T. J. and Kozlowski, W. and Caballero-Benitez, S. F. and Mekhov, I. B.}, month = mar, year = {2015}, pages = {113604}, file = {APS Snapshot:/home/wojtek/Zotero/storage/XLV69NXE/PhysRevLett.114.html:text/html;Full Text PDF:/home/wojtek/Zotero/storage/QINRWYWK/Elliott et al. - 2015 - Multipartite Entangled Spatial Modes of Ultracold .pdf:application/pdf} } @article{kozlowski_probing_2015, title = {Probing matter-field and atom-number correlations in optical lattices by global nondestructive addressing}, volume = {92}, url = {https://link.aps.org/doi/10.1103/PhysRevA.92.013613}, doi = {10.1103/PhysRevA.92.013613}, abstract = {We show that light scattering from an ultracold gas reveals not only density correlations, but also matter-field interference at its shortest possible distance in an optical lattice, which defines key properties such as tunneling and matter-field phase gradients. This signal can be enhanced by concentrating probe light between lattice sites rather than at density maxima. As addressing between two single sites is challenging, we focus on global nondestructive scattering, allowing probing order parameters, matter-field quadratures, and their squeezing. The scattering angular distribution displays peaks even if classical diffraction is forbidden and we derive generalized Bragg conditions. Light scattering distinguishes all phases in the Mott insulator–superfluid–Bose glass phase transition.}, number = {1}, urldate = {2019-02-07}, journal = {Physical Review A}, author = {Kozlowski, W. and Caballero-Benitez, S. F. and Mekhov, I. B.}, month = jul, year = {2015}, pages = {013613}, file = {APS Snapshot:/home/wojtek/Zotero/storage/2G9FVS7A/PhysRevA.92.html:text/html;Full Text PDF:/home/wojtek/Zotero/storage/V7VGLRNS/Kozlowski et al. - 2015 - Probing matter-field and atom-number correlations .pdf:application/pdf} } @article{granqvist_buffering_2012, title = {Buffering {Capacity} {Explains} {Signal} {Variation} in {Symbiotic} {Calcium} {Oscillations}}, volume = {160}, copyright = {© 2012 American Society of Plant Biologists. All Rights Reserved..}, issn = {0032-0889, 1532-2548}, url = {http://www.plantphysiol.org/content/160/4/2300}, doi = {10.1104/pp.112.205682}, abstract = {Legumes form symbioses with rhizobial bacteria and arbuscular mycorrhizal fungi that aid plant nutrition. A critical component in the establishment of these symbioses is nuclear-localized calcium (Ca2+) oscillations. Different components on the nuclear envelope have been identified as being required for the generation of the Ca2+ oscillations. Among these an ion channel, Doesn't Make Infections1, is preferentially localized on the inner nuclear envelope and a Ca2+ ATPase is localized on both the inner and outer nuclear envelopes. Doesn't Make Infections1 is conserved across plants and has a weak but broad similarity to bacterial potassium channels. A possible role for this cation channel could be hyperpolarization of the nuclear envelope to counterbalance the charge caused by the influx of Ca2+ into the nucleus. Ca2+ channels and Ca2+ pumps are needed for the release and reuptake of Ca2+ from the internal store, which is hypothesized to be the nuclear envelope lumen and endoplasmic reticulum, but the release mechanism of Ca2+ remains to be identified and characterized. Here, we develop a mathematical model based on these components to describe the observed symbiotic Ca2+ oscillations. This model can recapitulate Ca2+ oscillations, and with the inclusion of Ca2+-binding proteins it offers a simple explanation for several previously unexplained phenomena. These include long periods of frequency variation, changes in spike shape, and the initiation and termination of oscillations. The model also predicts that an increase in buffering capacity in the nucleoplasm would cause a period of rapid oscillations. This phenomenon was observed experimentally by adding more of the inducing signal.}, language = {en}, number = {4}, urldate = {2019-03-31}, journal = {Plant Physiology}, author = {Granqvist, Emma and Wysham, Derin and Hazledine, Saul and Kozlowski, Wojciech and Sun, Jongho and Charpentier, Myriam and Martins, Teresa Vaz and Haleux, Pauline and Tsaneva-Atanasova, Krasimira and Downie, J. Allan and Oldroyd, Giles E. D. and Morris, Richard J.}, month = dec, year = {2012}, pmid = {23027664}, pages = {2300--2310}, file = {Full Text PDF:/home/wojtek/Zotero/storage/5R7AQD46/Granqvist et al. - 2012 - Buffering Capacity Explains Signal Variation in Sy.pdf:application/pdf;Snapshot:/home/wojtek/Zotero/storage/XAFMQZKV/2300.html:text/html} }