en مگنتو اپتیک Magneto-Optics پژوهشي Research <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-weight:bold">The measurement of magnetic field generated by heart activity is crucial for the diagnosis and treatment of heart diseases and failures. Atomic magnetometers are an excellent choice for detecting bio-magnetic fields due to their comparable sensitivity to superconducting quantum interference devices, lower manufacturing costs, and lack of requirement for low temperatures. These magnetometers detect the magnetic field resulting from heart activity by measuring the Zeeman energy splitting and changes in laser light intensity as it passes through an alkali metal vapor cell. To improve the sensitivity of the measurements, this study presents a gradiometer design that utilizes two atomic magnetometers to eliminate environmental magnetic noise. By using a derivative technique, the homogeneous noises in both magnetometer channels are effectively eliminated. The gradiometer is capable of detecting the magnetic field produced by a frog&#39;s heart with a sensitivity of 860 fT/&radic;Hz even without magnetic shielding and in the presence of the Earth&#39;s field. This gradiometer design can be expanded to include multiple channels for mapping the heart&#39;s magnetic field.</span></span></span> Atomic magnetometer, Biomagnetism, Gradiometer, Noise cancellation, Zeeman splitting detection 155 164 http://ijop.ir/browse.php?a_code=A-10-950-1&slc_lang=en&sid=1 Maliheh Ranjbaran m.ranjbaran@iauctb.ac.ir 10031947532846005134 10031947532846005134 No Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran, Iran Reza sedeyan r.sedeyan@mail.sbu.ac.ir 10031947532846005135 10031947532846005135 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran Amin Zamani aminzamani.org@gmail.com 10031947532846005136 10031947532846005136 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran Mohammad Mehdi Tehranchi teranchi@sbu.ac.ir 10031947532846005137 10031947532846005137 Yes Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran ,Physics Department, Shahid Beheshti University, Tehran, Iran Seyed Mohammad Hosein Khalkhali m_khalkhali@khu.ac.ir 10031947532846005138 10031947532846005138 No Department of Physics, Kharazmi University, Tehran, Iran Seyedeh Mehri Hamidi m_hamidi@sbu.ac.ir 10031947532846005139 10031947532846005139 No Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran