BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:A. E. Afanas'ev DTSTART:20240904T134000Z DTEND:20240904T144000Z DTSTAMP:20260423T040007Z UID:QOART/17 DESCRIPTION:Title: Q uantum metrology with atom chip\nby A. E. Afanas'ev as part of Quantum Optics and Related Topics\n\n\nAbstract\nThe goal of quantum metrology is to increase the sensitivity of physical fields measuring. It can be achie ved by using quantum mechanics effects such as interferometry of quantum s tates\, squeezing\, etc. Quantum sensors used as instruments for high sens itivity measurements reached outstanding results in laboratory conditions. There is currently a growing trend towards outdoor experimentation. The m ain development trend is the decreasing of dimensions and power consumptio n of quantum sensor in comparison with used sensors in classical approache s. Increasing sensitivity of outdoor sensors will allows us to move to the next technological level.\nAmong various types of quantum sensors\, the s ensors using neutral atoms are promising. To increase the quantum senser s ensitivity the approach of atomic state interference is used.\nAtom interf erometry is considered as a platform for high precision fundamental experi ments and for solving numerous applied problems [1]. For instance\, microw ave atomic clock used interference pattern of Ramsey fringe for high stabi lity of frequency standards. The precision of quantum sensors is limited b y the quantum projection noise. Therefore\, the number of atoms forming th e interference pattern is the cornerstone of quantum sensor. To reach high precision of quantum sensors based on atom interferometry the effective s ource of cold atoms is necessary. There are three types of atoms sources c an be used for atom interferometry: (1) atomic beam\; (2) cold atoms in ma gneto-optical trap (MOT)\; (3) ultracold atoms trapped on atom chip. The u se of the first type of atom source leads to quantum sensors of large spat ial dimensions. Cold atoms from MOT are actively used in quantum sensors\, for instance\, in atomic gravimeter [2\,3]. The drawback of MOT as an ato mic source is the temperature of atomic ensemble. In case of sub-Doppler c ooling the temperature is about several microkelvins. Lower temperatures r equire evaporative cooling. Unfortunately\, MOT is not suitable for evapor ative cooling\, which is usually done in a magnetic trap.\nThe atom chip o peration is based on a cold atom trapping near the microwire. In this case a high gradient of magnetic field can be achieved relatively easy. Approa ch for ultracold atom source sensor baser on atom chip has been demonstrat ed with high bandwidth [4]. Until now\, most demonstrated atom chips have been technically sophisticated\, with multiple layers of microwires to coo l and trap atoms. We demonstrated single-layer atom chip which can be used as atom source for atom interferometry and quantum sensors [5]. The new t ype of single-layer atom chip developed\, which makes it possible to incre ase the number of atoms up to 5?107 [6]. The magnetic trapping of atoms gi ves the possibility to use evaporative cooling to reach the temperatures b elow 1 mkK. It gives us the possibility of coherent manipulations with ato mic ensemble.\n\nThe study was supported by the Russian Science Foundation \, grant No. 23-22-00255.\n\nReferences\n\n[1] R. Geiger\, et al.\, AVS Qu antum Sci. 2\, 024702 (2020).\n\n[2] V. Menoret\, et al.\, Sci Rep 8\, 123 00 (2018).\n\n[3] Pan-Wei Huang\, et al.\, Metrologia 56\, 045012 (2019).\ n\n[4] J. Rudolph\, et al.\, New J. Phys. 17\, 065001 (2015).\n\n[5] A.E. Afanasiev\, et al.\, Optics & Laser Technology\, 148\, 107698 (2022).\n\n[ 6] P. Skakunenko\, et al.\, Chinese Optics Letters\, 22\, 060201 (2024).\n LOCATION:https://researchseminars.org/talk/QOART/17/ END:VEVENT END:VCALENDAR