Searches for pseudo-magnetic spin couplings require implementation of techniques capable sensitive detection such interactions. While Spin-Exchange Relaxation Free (SERF) magnetometry is one the most powerful approaches enabling searches, it suffers from a strong magnetic coupling, deteriorating coupling sensitivity. To address this problem, here, we compare, via numerical simulations, performance SERF magnetometer and noble-gas-alkali-metal co-magnetometer, operating in so-called...

We demonstrate an experimental technique for the quantum-state tomography of collective qutrit states a room-temperature alkali-metal vapor. It is based on measurements polarization light traversing vapor subjected to magnetic field. To assess technique's robustness against errors, investigations are supported with numerical simulations. This not only allows us determine fidelity reconstructed states, but also analyze quality reconstruction specific parameters, such as tuning and number...

In this paper we introduce and investigate the concept of a perfect quantum protractor, pure state $|\psi\rangle\in\mathcal{H}$ that generates three different orthogonal bases $\mathcal{H}$ under rotations around each perpendicular axes. Such states can be understood as maximal uncertainty with regards to components angular momentum operator, prove they maximise various entropic variance-based measures such uncertainty. We argue protractors only exist for systems well-defined total $j$, do...

Reconstruction of a quantum state is prime importance for quantum-information science. Specifically, means efficient determination atoms room-temperature vapor may enable applications in computations and cryptography. To step toward such applications, here we present method reconstruction collective density matrix an atomic ensemble, consisting with $F=1$ ground state. Such long-lived often encountered real systems (e.g., potassium, sodium, rubidium) hence be practically utilized. Our...

Nonlinear magnetic interactions provide access to complex quantum spin dynamics and thus enable the study of intriguing physical phenomena. However, these are often dominated by linear Zeeman effect, which can complicate system make their analysis more challenging. In this article, we theoretically experimentally introduce a method induce quadratic effect while effectively compensating for its counterpart. By isolating contributions, demonstrate analyze controlled superposition generation...

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We demonstrate a novel experimental technique for quantum-state tomography of the collective density matrix. It is based on measurements polarization light, traversing atomic vapor. To assess technique's robustness against errors, investigations are supported with numerical simulations. This not only allows to determine fidelity reconstruction, but also analyze quality reconstruction specific parameters light tuning and number measurements). By utilizing so-called conditional number, we that...

In this paper, we investigate the coherent control over a complex multi-level atomic system using stimulated Raman adiabatic passage (STIRAP). Based on example of rubidium-87 atoms, excited with circularly-polarized light at D1 line, demonstrate ability to decompose into three- and four-level subsystems independently interacting beams. Focusing system, that presence an additional state significantly affects dynamics evolution. Specifically, it is shown that, through appropriate tuning beams,...

Abstract Searches for pseudo-magnetic spin couplings require implementation of techniques capable sensitive detection such interactions. While Spin-Exchange Relaxation Free (SERF) magnetometry is one the most powerful approaches enabling searches, it suffers from a strong magnetic coupling, deteriorating coupling sensitivity. To address this problem, here, we compare, via numerical simulations, performance SERF magnetometer and noble-gas-alkali-metal co-magnetometer, operating in so-called...

In this paper, we investigate the coherent control over a complex multilevel atomic system using stimulated Raman adiabatic passage. Based on example of $^{87}\mathrm{Rb}$ atoms, excited with circularly polarized light at ${D}_{1}$ line, demonstrate ability to decompose into three- and four-level subsystems independently interacting beams. Focusing system, that presence an additional state significantly affects dynamics evolution. Specifically, it is shown that, through appropriate tuning...

Quantum-state tomography is a crucial ingredient in quantum-computations and engineering. Measurement of state fidelity fundamental for determination the performance various quantum protocols their specific implementations. Tomography can be also used error correction [1]. Principally, two types objects needs to performed. The first measurements done over photons which are good transmitters information. other on “atomic” systems, offers ability manipulate Atomic gasses among most promises...