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The blue points represent the [MOT](#mot-section) steps with the MOT, compressed MOT and the optical molasses and the orange the [magnetic trap](#magnetic-trap-section). The green points denote the optical dipole trap steps with the loading and the final evaporation. The dashed red line represent the Bose-Einstein condensation threshold for which the de Broglie wavelength is equal to the typical inter-particle distance. ©Figure from @marolleau_quantum_2022.\n``` \n","key":"zETIhqY8Xo"},{"type":"admonition","kind":"tip","children":[{"type":"admonitionTitle","children":[{"type":"text","value":"What we knew, what is new ?","position":{"start":{"line":27,"column":1},"end":{"line":27,"column":1}},"key":"W3uCISi7Q9"}],"key":"y05wkYfIBd"},{"type":"paragraph","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"The metastable helium experiment I worked on during my thesis is the oldest French ","key":"w316yEYfaa"},{"type":"abbreviation","title":"Bose-Einstein Condensate","children":[{"type":"text","value":"BEC","key":"gFh8bvT2sJ"}],"key":"a9jzrFr921"},{"type":"text","value":" still in activity: it needed a facelift to get back on tracks.  All the lasers used in this work were changed (","key":"ADKlIjWrfn"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"cooling","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"NJkVCjsSyV"}],"identifier":"mot-subsection","label":"mot-subsection","kind":"heading","template":"{name}","resolved":true,"html_id":"mot-subsection","remote":true,"url":"/bec-mot","dataUrl":"/bec-mot.json","key":"X2xNSU78tn"},{"type":"text","value":", ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"EZ5s8JfbMl"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"Raman","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"ecIBtCIX0F"}],"identifier":"raman-transfer","label":"raman-transfer","kind":"heading","template":"Section %s","enumerator":"2","resolved":true,"html_id":"raman-transfer","remote":true,"url":"/bec-odt","dataUrl":"/bec-odt.json","key":"U3nWdBNfjl"},{"type":"text","value":"/","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"AEQCXcjZdN"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"Bragg","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"xRnuYZiTXO"}],"identifier":"bragg_definition","label":"bragg_definition","kind":"heading","template":"Section %s","enumerator":"1","resolved":true,"html_id":"bragg-definition","remote":true,"url":"/bec-bragg","dataUrl":"/bec-bragg.json","key":"Ro22EkTLKc"},{"type":"text","value":" and ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"XNH0RWyyST"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"dipole trap","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"me22ZnIqlx"}],"identifier":"dipole-trap","label":"dipole-trap","kind":"heading","template":"Section %s","enumerator":"1","resolved":true,"html_id":"dipole-trap","remote":true,"url":"/bec-odt","dataUrl":"/bec-odt.json","key":"S1kdlk7Tr1"},{"type":"text","value":"). The sequencer was also changed: the details of its operation are left in the ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"VBp8jIwweS"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"appendix","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"B7wstbe8gk"}],"identifier":"adwin_to_qc3","label":"adwin_to_qc3","kind":"heading","template":"Section %s","enumerator":"1","resolved":true,"html_id":"adwin-to-qc3","remote":true,"url":"/qcontrol3","dataUrl":"/qcontrol3.json","key":"MTXrJ9FiDG"},{"type":"text","value":". This replacement and the writing of all the driver took a non-negligible time of this work. The ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"pVNE8ubaVO"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"watercooling","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"xlYXzCiAan"}],"identifier":"water_cooling_experiment","label":"water_cooling_experiment","kind":"heading","template":"Section %s","enumerator":"3","resolved":true,"html_id":"water-cooling-experiment","remote":true,"url":"/technical-notes","dataUrl":"/technical-notes.json","key":"Q5yTJHZUOP"},{"type":"text","value":" pipes of the room were also changed, and we faced vacuum issues during months. One led us to replace the metastable helium ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"gzqjZP9XAg"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"source","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"bgdQQXCJPA"}],"identifier":"he-source-section","label":"he-source-section","kind":"heading","template":"Section %s","enumerator":"2","resolved":true,"html_id":"he-source-section","remote":true,"url":"/bec-mot","dataUrl":"/bec-mot.json","key":"fWCtp2r3Dx"},{"type":"text","value":". Some work was done on the optical setup but no major change. I also worked on the ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"oKY1yDYb9C"},{"type":"crossReference","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"children":[{"type":"text","value":"shaping of the laser pulses","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"HalmFveV9a"}],"identifier":"pi_pulse_optimization","label":"pi_pulse_optimization","kind":"heading","template":"Section %s","enumerator":"4","resolved":true,"html_id":"pi-pulse-optimization","remote":true,"url":"/bec-bragg","dataUrl":"/bec-bragg.json","key":"G6OStNsj9F"},{"type":"text","value":" to realize a momentum selective atomic interferometer, but this project was mainly investigated and developed by Charlie ","position":{"start":{"line":29,"column":1},"end":{"line":29,"column":1}},"key":"r8TgMHvGqk"},{"type":"cite","identifier":"leprince_phase_2024","label":"leprince_phase_2024","kind":"narrative","position":{"start":{"line":29,"column":965},"end":{"line":29,"column":985}},"children":[{"type":"text","value":"Leprince (2024)","key":"a8Fn4RGsDb"}],"enumerator":"3","key":"CicIGHlLoN"},{"type":"text","value":", who was a PhD student with whom I worked on the experiment for my entire PhD thesis. 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I. (2015). Atomic Hong–Ou–Mandel experiment. <i>Nature</i>, <i>520</i>(7545), 66–68. <a target=\"_blank\" rel=\"noreferrer\" href=\"https://doi.org/10.1038/nature14331\">10.1038/nature14331</a>","url":"https://doi.org/10.1038/nature14331"},"dussarrat_two_particle_2017":{"label":"dussarrat_two_particle_2017","enumerator":"2","doi":"10.1103/PhysRevLett.119.173202","html":"Dussarrat, P., Perrier, M., Imanaliev, A., Lopes, R., Aspect, A., Cheneau, M., Boiron, D., & Westbrook, C. I. (2017). Two-Particle Four-Mode Interferometer for Atoms. <i>Physical Review Letters</i>, <i>119</i>(17), 173202. <a target=\"_blank\" rel=\"noreferrer\" href=\"https://doi.org/10.1103/PhysRevLett.119.173202\">10.1103/PhysRevLett.119.173202</a>","url":"https://doi.org/10.1103/PhysRevLett.119.173202"},"leprince_phase_2024":{"label":"leprince_phase_2024","enumerator":"3","html":"Leprince, C. (2024). <i>Phase control and pulse shaping in Bragg diffraction for quantum atom optics: From matter-wave interferences to a Bell’s inequality test</i> [Phdthesis, Université Paris-Saclay]. <a target=\"_blank\" rel=\"noreferrer\" href=\"https://theses.fr/s247200\">https://theses.fr/s247200</a>","url":"https://theses.fr/s247200"},"leprince_2024_coherent":{"label":"leprince_2024_coherent","enumerator":"4","html":"Leprince, C., Gondret, V., Lamirault, C., Dias, R., Marolleau, Q., Boiron, D., & Westbrook, C. I. (2024). <i>Coherent coupling of momentum states: selectivity and phase control</i>. Submitted to Phys. Rev. A. <a target=\"_blank\" rel=\"noreferrer\" href=\"https://arxiv.org/pdf/2411.09284\">https://arxiv.org/pdf/2411.09284</a>","url":"https://arxiv.org/pdf/2411.09284"}}}},"footer":{"navigation":{"prev":{"title":"Assessing the degree of entanglement of thermal Gaussian states with 2- and 4-body correlation functions","short_title":"Entanglement via g2 and g4","url":"/entanglement-4correlation","group":"On the entanglement of quasi-particles in a Bose-Einstein condensate"},"next":{"title":"From helium to a magneto-optical trap of metastable helium","short_title":"From helium to a magneto-optical trap of metastable helium","url":"/bec-mot","group":"On the entanglement of quasi-particles in a Bose-Einstein condensate"}}},"domain":"http://localhost:3011"}