{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/8484"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/8484","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Explorations of quantum decoherence phenomena","abstract":"This thesis describes the experimental exploration of quantum decoherence using discrete and continuous-time decoherence maps. The experimental methodology uses liquid-state nuclear magnetic resonance spectroscopy techniques. Initially, a brief discussion of coherent control methods is given. Then, a detailed discussion of the decoherent control methods is presented. These methods describe how strong measurements can be emulated in an ensemble system by using pulsed magnetic field gradients, and how NMR decoupling techniques can be used to implement partial trace operations. Next, using quantum erasers we explore the stability of three-particle systems under different entangling interactions. With a two-spin system we illustrate the essential features of quantum erasers. The extension to three-spins allows us to use the pair of orthogonal decoherent operations used in quantum erasers to probe the two classes of entanglement in three-particle systems: the GHZ state and the W state. Finally, we develop a decoherence model of a decohering two-level system coupled to an environment with a few degrees of freedom. The couplings are of the [sigma]z [sigma]z type and only induce coherence damping. By introducing a stochastic evolution on the environment, the resulting randomization of the environment phases causes loss of information over the environment degrees of freedom and decohers the system. Control parameters in the stochastic driving of the environment were used to vary the rates of decoherence on the system, thereby allowing the establishment of a scaling law that related control parameters to decay rates.","abstract_html":"This thesis describes the experimental exploration of quantum decoherence using discrete and continuous-time decoherence maps. The experimental methodology uses liquid-state nuclear magnetic resonance spectroscopy techniques. Initially, a brief discussion of coherent control methods is given. Then, a detailed discussion of the decoherent control methods is presented. These methods describe how strong measurements can be emulated in an ensemble system by using pulsed magnetic field gradients, and how NMR decoupling techniques can be used to implement partial trace operations. Next, using quantum erasers we explore the stability of three-particle systems under different entangling interactions. With a two-spin system we illustrate the essential features of quantum erasers. The extension to three-spins allows us to use the pair of orthogonal decoherent operations used in quantum erasers to probe the two classes of entanglement in three-particle systems: the GHZ state and the W state. Finally, we develop a decoherence model of a decohering two-level system coupled to an environment with a few degrees of freedom. The couplings are of the [sigma]z [sigma]z type and only induce coherence damping. By introducing a stochastic evolution on the environment, the resulting randomization of the environment phases causes loss of information over the environment degrees of freedom and decohers the system. Control parameters in the stochastic driving of the environment were used to vary the rates of decoherence on the system, thereby allowing the establishment of a scaling law that related control parameters to decay rates.","abstract_has_math":false,"creators":["Teklemariam, Grum, 1965-"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Physics.","school":null,"contributors":[],"advisors":["David G. Cory and Edward H. Farhi."],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-22T22:22:08Z","subjects":["Physics."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/8484","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["David G. Cory and Edward H. Farhi."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Dept. of Physics."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Dept. of Physics."]},{"key":"dc:creator","label":"Author","values":["Teklemariam, Grum, 1965-"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2005-08-23T20:31:56Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2005-08-23T20:31:56Z"]},{"key":"dc:date.issued","label":"Date","values":["2002"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/8484"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.","Includes bibliographical references (p. 77-80)."]},{"key":"dc:description.abstract","label":"Abstract","values":["This thesis describes the experimental exploration of quantum decoherence using discrete and continuous-time decoherence maps. The experimental methodology uses liquid-state nuclear magnetic resonance spectroscopy techniques. Initially, a brief discussion of coherent control methods is given. Then, a detailed discussion of the decoherent control methods is presented. These methods describe how strong measurements can be emulated in an ensemble system by using pulsed magnetic field gradients, and how NMR decoupling techniques can be used to implement partial trace operations. Next, using quantum erasers we explore the stability of three-particle systems under different entangling interactions. With a two-spin system we illustrate the essential features of quantum erasers. The extension to three-spins allows us to use the pair of orthogonal decoherent operations used in quantum erasers to probe the two classes of entanglement in three-particle systems: the GHZ state and the W state. Finally, we develop a decoherence model of a decohering two-level system coupled to an environment with a few degrees of freedom. The couplings are of the [sigma]z [sigma]z type and only induce coherence damping. By introducing a stochastic evolution on the environment, the resulting randomization of the environment phases causes loss of information over the environment degrees of freedom and decohers the system. Control parameters in the stochastic driving of the environment were used to vary the rates of decoherence on the system, thereby allowing the establishment of a scaling law that related control parameters to decay rates."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Explorations of quantum decoherence phenomena"]}]}],"canonical_facts":{"dc:contributor.advisor":["David G. Cory and Edward H. Farhi."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Physics."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Physics."],"dc:creator":["Teklemariam, Grum, 1965-"],"dc:date.accessioned":["2005-08-23T20:31:56Z"],"dc:date.available":["2005-08-23T20:31:56Z"],"dc:date.issued":["2002"],"dc:description":["Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.","Includes bibliographical references (p. 77-80)."],"dc:description.abstract":["This thesis describes the experimental exploration of quantum decoherence using discrete and continuous-time decoherence maps. The experimental methodology uses liquid-state nuclear magnetic resonance spectroscopy techniques. Initially, a brief discussion of coherent control methods is given. Then, a detailed discussion of the decoherent control methods is presented. These methods describe how strong measurements can be emulated in an ensemble system by using pulsed magnetic field gradients, and how NMR decoupling techniques can be used to implement partial trace operations. Next, using quantum erasers we explore the stability of three-particle systems under different entangling interactions. With a two-spin system we illustrate the essential features of quantum erasers. The extension to three-spins allows us to use the pair of orthogonal decoherent operations used in quantum erasers to probe the two classes of entanglement in three-particle systems: the GHZ state and the W state. Finally, we develop a decoherence model of a decohering two-level system coupled to an environment with a few degrees of freedom. The couplings are of the [sigma]z [sigma]z type and only induce coherence damping. By introducing a stochastic evolution on the environment, the resulting randomization of the environment phases causes loss of information over the environment degrees of freedom and decohers the system. Control parameters in the stochastic driving of the environment were used to vary the rates of decoherence on the system, thereby allowing the establishment of a scaling law that related control parameters to decay rates."],"dc:description.degree":["Ph.D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/8484"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Physics."],"dc:title":["Explorations of quantum decoherence phenomena"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:22:08Z"}