The Experts below are selected from a list of 13041 Experts worldwide ranked by ideXlab platform
Dan Stamperkurn - One of the best experts on this subject based on the ideXlab platform.
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high resolution magnetometry with a spinor bose einstein condensate
Physical Review Letters, 2007Co-Authors: M Vengalattore, James Higbie, Sabrina Leslie, Jennie Guzman, Lorraine Sadler, Dan StamperkurnAbstract:We demonstrate a precise magnetic microscope based on direct imaging of the Larmor precession of a $^{87}\mathrm{Rb}$ spinor Bose-Einstein condensate. This magnetometer attains a field sensitivity of $8.3\text{ }\text{ }\mathrm{pT}/{\mathrm{Hz}}^{1/2}$ over a measurement area of $120\text{ }\text{ }\ensuremath{\mu}{\mathrm{m}}^{2}$, an improvement over the low-frequency field sensitivity of modern SQUID Magnetometers. The achieved phase sensitivity is close to the atom shot-noise limit, estimated as $0.15\text{ }\text{ }\mathrm{pT}/{\mathrm{Hz}}^{1/2}$ for a unity duty cycle measurement, suggesting the possibilities of spatially resolved spin-squeezed magnetometry. This magnetometer marks a significant application of degenerate atomic gases to metrology.
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high resolution magnetometry with a spinor bose einstein condensate
Physical Review Letters, 2007Co-Authors: M Vengalattore, James Higbie, Sabrina Leslie, Jennie Guzman, Lorraine Sadler, Dan StamperkurnAbstract:We demonstrate a precise magnetic microscope based on direct imaging of the Larmor precession of a 87Rb spinor Bose-Einstein condensate. This magnetometer attains a field sensitivity of 8.3 pT/Hz1/2 over a measurement area of 120 microm2, an improvement over the low-frequency field sensitivity of modern SQUID Magnetometers. The achieved phase sensitivity is close to the atom shot-noise limit, estimated as 0.15 pT/Hz1/2 for a unity duty cycle measurement, suggesting the possibilities of spatially resolved spin-squeezed magnetometry. This magnetometer marks a significant application of degenerate atomic gases to metrology.
Jianhua Liu - One of the best experts on this subject based on the ideXlab platform.
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polarization and fundamental sensitivity of text 39 k text 133 cs text 85 rb text 21 ne co Magnetometers
arXiv: Atomic Physics, 2018Co-Authors: Jianhua Liu, Jiancheng Fang, Dongyang Jing, Wei Quan, Lin Zhuang, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (HOPSERF) atomic co-Magnetometers make ultrahigh sensitivity measurement of inertia achievable. The wall relaxation rate has a big effect on the polarization and fundamental sensitivity for the co-magnetometer, but it is often neglected in the experiments. However, there is almost no work about the systematic analysis of the influence factors on the polarization and the fundamental sensitivity of the HOPSERF co-Magnetometers. Here, we systematically study the polarization and the fundamental sensitivity of 39K-85Rb-21Ne and 133Cs-85Rb-21Ne HOPSERF co-Magnetometers with low polarization limit and the wall relaxation rate. The 21Ne number density, the power density and wavelength of pump beam will affect the polarization greatly by affecting the pumping rate of pump beam. We obtain a general formula on the fundamental sensitivity of the HOPSERF co-Magnetometers due to shot-noise and the fundamental sensitivity changes with multiple systemic parameters, where the suitable number density of buffer gas and quench gas make the fundamental sensitivity highest. The fundamental sensitivity $7.5355\times10^{-11}$ $\rm rad/s/Hz^{1/2}$ of 133Cs-85Rb-21Ne co-magnetometer is higher than the ultimate theoretical sensitivity $2\times10^{-10}$ $\rm rad/s/Hz^{1/2}$ of K-21Ne co-magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
Scientific Reports, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on 39K-85Rb-4He and 133Cs-85Rb-4He respectively. Then we found that 85Rb polarization varies with the number density of buffer gas 4He and quench gas N2, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10−18 T) with 39K-85Rb-4He magnetometer between above two types of Magnetometers when 85Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10−2 aT/Hz 1/2, which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
arXiv: Atomic Physics, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the $^{\text{85}}$Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He and $^{\text{133}}$Cs-$^{\text{85}}$Rb-$^{\text{4}}$He respectively. Then we found that $^{\text{85}}$Rb polarization varies with the number density of buffer gas $^{\text{4}}$He and quench gas N$_{\text{2}}$, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of $1.5073$ $aT/Hz^{1/2}$ ($1$ $aT=10^{-18}$ $T$) with $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He magnetometer between above two types of Magnetometers when $^{\text{85}}$Rb polarization is $0.1116$. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to $1.8359\times10^{-2}$ $aT/Hz^{1/2}$, which is higher than the shot-noise-limited sensitivity of $1$ $aT/Hz^{1/2}$ of K SERF atomic magnetometer.
M V Romalis - One of the best experts on this subject based on the ideXlab platform.
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multi channel atomic magnetometer for magnetoencephalography a configuration study
NeuroImage, 2014Co-Authors: Kiwoong Kim, Samo Begus, H Xia, Seungkyun Lee, Vojko Jazbinsek, Zvonko Trontelj, M V RomalisAbstract:Atomic Magnetometers are emerging as an alternative to SQUID Magnetometers for detection of biological magnetic fields. They have been used to measure both the magnetocardiography (MCG) and magnetoencephalography (MEG) signals. One of the virtues of the atomic Magnetometers is their ability to operate as a multi-channel detector while using many common elements. Here we study two configurations of such a multi-channel atomic magnetometer optimized for MEG detection. We describe measurements of auditory evoked fields (AEF) from a human brain as well as localization of dipolar phantoms and auditory evoked fields. A clear N100m peak in AEF was observed with a signal-to-noise ratio of higher than 10 after averaging of 250 stimuli. Currently the intrinsic magnetic noise level is 4fTHz(-1/2) at 10Hz. We compare the performance of the two systems in regards to current source localization and discuss future development of atomic MEG systems.
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subfemtotesla scalar atomic magnetometry using multipass cells
Physical Review Letters, 2013Co-Authors: Dong Sheng, Shuguang Li, Nezih Dural, M V RomalisAbstract:: Scalar atomic Magnetometers have many attractive features but their sensitivity has been relatively poor. We describe a Rb scalar gradiometer using two multipass optical cells. We use a pump-probe measurement scheme to suppress spin-exchange relaxation and two probe pulses to find the spin precession zero crossing times with a resolution of 1 psec. We realize a magnetic field sensitivity of 0.54 fT/Hz(1/2), which improves by an order of magnitude the best scalar magnetometer sensitivity and exceeds, for example, the quantum limit set by the spin-exchange collisions for a scalar magnetometer with the same measurement volume operating in a continuous regime.
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subfemtotesla scalar atomic magnetometry using multipass cells
Physical Review Letters, 2013Co-Authors: Dong Sheng, Nezih Dural, M V RomalisAbstract:Scalar atomic Magnetometers have many attractive features but their sensitivity has been relatively poor. We describe a Rb scalar gradiometer using two multipass optical cells. We use a pump-probe measurement scheme to suppress spin-exchange relaxation and two probe pulses to find the spin precession zero crossing times with a resolution of 1 psec. We realize a magnetic field sensitivity of $0.54\text{ }\text{ }\mathrm{fT}/{\mathrm{Hz}}^{1/2}$, which improves by an order of magnitude the best scalar magnetometer sensitivity and exceeds, for example, the quantum limit set by the spin-exchange collisions for a scalar magnetometer with the same measurement volume operating in a continuous regime.
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A subfemtotesla multichannel atomic magnetometer
Nature, 2003Co-Authors: I. K. Kominis, THOMAS W KORNACK, J. C. Allred, M V RomalisAbstract:The magnetic field is one of the most fundamental and ubiquitous physical observables, carrying information about all electromagnetic phenomena. For the past 30 years, superconducting quantum interference devices (SQUIDs) operating at 4 K have been unchallenged as ultrahigh-sensitivity magnetic field detectors^ 1 , with a sensitivity reaching down to 1 fT Hz^-1/2 (1 fT = 10^-15 T). They have enabled, for example, mapping of the magnetic fields produced by the brain, and localization of the underlying electrical activity (magnetoencephalography). Atomic Magnetometers, based on detection of Larmor spin precession of optically pumped atoms, have approached similar levels of sensitivity using large measurement volumes^ 2 , 3 , but have much lower sensitivity in the more compact designs required for magnetic imaging applications^ 4 . Higher sensitivity and spatial resolution combined with non-cryogenic operation of atomic Magnetometers would enable new applications, including the possibility of mapping non-invasively the cortical modules in the brain. Here we describe a new spin-exchange relaxation-free (SERF) atomic magnetometer, and demonstrate magnetic field sensitivity of 0.54 fT Hz^-1/2 with a measurement volume of only 0.3 cm^3. Theoretical analysis shows that fundamental sensitivity limits of this device are below 0.01 fT Hz^-1/2. We also demonstrate simple multichannel operation of the magnetometer, and localization of magnetic field sources with a resolution of 2 mm.
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high sensitivity atomic magnetometer unaffected by spin exchange relaxation
Physical Review Letters, 2002Co-Authors: Joel C Allred, R N Lyman, THOMAS W KORNACK, M V RomalisAbstract:Alkali-metal Magnetometers compete with SQUID detectors as the most sensitive magnetic field sensors. Their sensitivity is limited by relaxation due to spin-exchange collisions. We demonstrate a K magnetometer in which spin-exchange relaxation is completely eliminated by operating at high K density and low magnetic field. Direct measurements of the signal-to-noise ratio give a magnetometer sensitivity of $10\text{ }\mathrm{f}\mathrm{T}\text{ }\mathrm{H}{\mathrm{z}}^{\mathrm{\ensuremath{-}}\mathrm{1}\mathrm{/}\mathrm{2}}$, limited by magnetic noise produced by Johnson currents in the magnetic shields. We extend a previous theoretical analysis of spin exchange in low magnetic fields to arbitrary spin polarizations and estimate the shot-noise limit of the magnetometer to be $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}18}\text{ }\mathrm{T}\text{ }\mathrm{H}{\mathrm{z}}^{\mathrm{\ensuremath{-}}\mathrm{1}\mathrm{/}\mathrm{2}}$.
Wuming Liu - One of the best experts on this subject based on the ideXlab platform.
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polarization and fundamental sensitivity of text 39 k text 133 cs text 85 rb text 21 ne co Magnetometers
arXiv: Atomic Physics, 2018Co-Authors: Jianhua Liu, Jiancheng Fang, Dongyang Jing, Wei Quan, Lin Zhuang, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (HOPSERF) atomic co-Magnetometers make ultrahigh sensitivity measurement of inertia achievable. The wall relaxation rate has a big effect on the polarization and fundamental sensitivity for the co-magnetometer, but it is often neglected in the experiments. However, there is almost no work about the systematic analysis of the influence factors on the polarization and the fundamental sensitivity of the HOPSERF co-Magnetometers. Here, we systematically study the polarization and the fundamental sensitivity of 39K-85Rb-21Ne and 133Cs-85Rb-21Ne HOPSERF co-Magnetometers with low polarization limit and the wall relaxation rate. The 21Ne number density, the power density and wavelength of pump beam will affect the polarization greatly by affecting the pumping rate of pump beam. We obtain a general formula on the fundamental sensitivity of the HOPSERF co-Magnetometers due to shot-noise and the fundamental sensitivity changes with multiple systemic parameters, where the suitable number density of buffer gas and quench gas make the fundamental sensitivity highest. The fundamental sensitivity $7.5355\times10^{-11}$ $\rm rad/s/Hz^{1/2}$ of 133Cs-85Rb-21Ne co-magnetometer is higher than the ultimate theoretical sensitivity $2\times10^{-10}$ $\rm rad/s/Hz^{1/2}$ of K-21Ne co-magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
Scientific Reports, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on 39K-85Rb-4He and 133Cs-85Rb-4He respectively. Then we found that 85Rb polarization varies with the number density of buffer gas 4He and quench gas N2, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10−18 T) with 39K-85Rb-4He magnetometer between above two types of Magnetometers when 85Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10−2 aT/Hz 1/2, which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
arXiv: Atomic Physics, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the $^{\text{85}}$Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He and $^{\text{133}}$Cs-$^{\text{85}}$Rb-$^{\text{4}}$He respectively. Then we found that $^{\text{85}}$Rb polarization varies with the number density of buffer gas $^{\text{4}}$He and quench gas N$_{\text{2}}$, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of $1.5073$ $aT/Hz^{1/2}$ ($1$ $aT=10^{-18}$ $T$) with $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He magnetometer between above two types of Magnetometers when $^{\text{85}}$Rb polarization is $0.1116$. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to $1.8359\times10^{-2}$ $aT/Hz^{1/2}$, which is higher than the shot-noise-limited sensitivity of $1$ $aT/Hz^{1/2}$ of K SERF atomic magnetometer.
Dongyang Jing - One of the best experts on this subject based on the ideXlab platform.
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polarization and fundamental sensitivity of text 39 k text 133 cs text 85 rb text 21 ne co Magnetometers
arXiv: Atomic Physics, 2018Co-Authors: Jianhua Liu, Jiancheng Fang, Dongyang Jing, Wei Quan, Lin Zhuang, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (HOPSERF) atomic co-Magnetometers make ultrahigh sensitivity measurement of inertia achievable. The wall relaxation rate has a big effect on the polarization and fundamental sensitivity for the co-magnetometer, but it is often neglected in the experiments. However, there is almost no work about the systematic analysis of the influence factors on the polarization and the fundamental sensitivity of the HOPSERF co-Magnetometers. Here, we systematically study the polarization and the fundamental sensitivity of 39K-85Rb-21Ne and 133Cs-85Rb-21Ne HOPSERF co-Magnetometers with low polarization limit and the wall relaxation rate. The 21Ne number density, the power density and wavelength of pump beam will affect the polarization greatly by affecting the pumping rate of pump beam. We obtain a general formula on the fundamental sensitivity of the HOPSERF co-Magnetometers due to shot-noise and the fundamental sensitivity changes with multiple systemic parameters, where the suitable number density of buffer gas and quench gas make the fundamental sensitivity highest. The fundamental sensitivity $7.5355\times10^{-11}$ $\rm rad/s/Hz^{1/2}$ of 133Cs-85Rb-21Ne co-magnetometer is higher than the ultimate theoretical sensitivity $2\times10^{-10}$ $\rm rad/s/Hz^{1/2}$ of K-21Ne co-magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
Scientific Reports, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on 39K-85Rb-4He and 133Cs-85Rb-4He respectively. Then we found that 85Rb polarization varies with the number density of buffer gas 4He and quench gas N2, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10−18 T) with 39K-85Rb-4He magnetometer between above two types of Magnetometers when 85Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10−2 aT/Hz 1/2, which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.
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the polarization and the fundamental sensitivity of 39 k 133 cs 85 rb 4 he hybrid optical pumping spin exchange relaxation free atomic Magnetometers
arXiv: Atomic Physics, 2017Co-Authors: Jiancheng Fang, Jianhua Liu, Dongyang Jing, Liangliang Wang, Wei Quan, Wuming LiuAbstract:The hybrid optical pumping spin exchange relaxation free (SERF) atomic Magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the $^{\text{85}}$Rb polarization of two types of hybrid optical pumping SERF Magnetometers based on $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He and $^{\text{133}}$Cs-$^{\text{85}}$Rb-$^{\text{4}}$He respectively. Then we found that $^{\text{85}}$Rb polarization varies with the number density of buffer gas $^{\text{4}}$He and quench gas N$_{\text{2}}$, pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of $1.5073$ $aT/Hz^{1/2}$ ($1$ $aT=10^{-18}$ $T$) with $^{\text{39}}$K-$^{\text{85}}$Rb-$^{\text{4}}$He magnetometer between above two types of Magnetometers when $^{\text{85}}$Rb polarization is $0.1116$. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to $1.8359\times10^{-2}$ $aT/Hz^{1/2}$, which is higher than the shot-noise-limited sensitivity of $1$ $aT/Hz^{1/2}$ of K SERF atomic magnetometer.
