Researchers have demonstrated coherent control of the fine-structure qubit in neutral strontium atoms trapped in an optical lattice. The qubit is encoded in the metastable ³P₂ and ³P₀ states, coupled by a Raman transition. Using a magnetic quadrupole transition, they demonstrated coherent state initialization of this THz qubit. They observed Rabi oscillations with over 60 coherent cycles and single-qubit rotations on the microsecond scale. Spin-echo measurements showed coherence times of tens of milliseconds. These results pave the way for fast quantum information processors and highly tunable quantum simulators with two-electron atoms. Neutral atoms are promising for quantum computing and simulation due to their long coherence times and scalable architecture. Two-electron atoms offer rich level structures for high-quality qubit encoding. Coupling ground and metastable states via optical clock transitions enables long coherence times and access to Rydberg states. However, ultra-narrow optical transitions limit speed and are sensitive to atomic motion and laser phase noise. Faster and more robust qubit rotations can be achieved by coupling states with lower energy splitting using a coherent Raman transition. This method has been used in nuclear spin states of Yb and Sr. These nuclear-spin qubits have enabled high-fidelity gates, erasure conversion, and mid-circuit operations. A complementary encoding of information in electronic degrees of freedom using metastable fine-structure states has been proposed, similar to schemes used in ions. In contrast to nuclear spin states, which require a magnetic field for qubit splitting, fine-structure states have a natural frequency splitting on the terahertz scale. Although this makes state-insensitive trapping challenging, it is advantageous for state preparation and readout. Combining with existing optical and nuclear qubits, this fine-structure qubit can unlock the full potential of the level scheme, enabling new functionalities like optical qutrits, single-photon transitions to Rydberg states with fast qubit rotations, and mid-circuit readout operations. The researchers experimentally demonstrated core capabilities of a fine-structure qubit using Sr atoms trapped in an optical lattice. The qubit is encoded in the metastable triplet states |↑⟩ and |↓⟩, separated by about 17 THz. These states are coupled via a two-photon Raman transition through the triplet state |s⟩. They demonstrated fast two-photon Rabi oscillations with frequencies up to 2π×400 kHz and studied their decoherence mechanisms. They showed proof-of-principle read-out methods with about 96% detection efficiency for mid-circuit read-out. They also investigated the coherence of the fine-structure qubit with Ramsey and spin-echo measurements. The experimental setup involved loading about 10⁵ ⁸⁸Sr atoms into a 3D optical lattice. They performed resolved sideband cooling on the ¹S₀-³P₁ transition atResearchers have demonstrated coherent control of the fine-structure qubit in neutral strontium atoms trapped in an optical lattice. The qubit is encoded in the metastable ³P₂ and ³P₀ states, coupled by a Raman transition. Using a magnetic quadrupole transition, they demonstrated coherent state initialization of this THz qubit. They observed Rabi oscillations with over 60 coherent cycles and single-qubit rotations on the microsecond scale. Spin-echo measurements showed coherence times of tens of milliseconds. These results pave the way for fast quantum information processors and highly tunable quantum simulators with two-electron atoms. Neutral atoms are promising for quantum computing and simulation due to their long coherence times and scalable architecture. Two-electron atoms offer rich level structures for high-quality qubit encoding. Coupling ground and metastable states via optical clock transitions enables long coherence times and access to Rydberg states. However, ultra-narrow optical transitions limit speed and are sensitive to atomic motion and laser phase noise. Faster and more robust qubit rotations can be achieved by coupling states with lower energy splitting using a coherent Raman transition. This method has been used in nuclear spin states of Yb and Sr. These nuclear-spin qubits have enabled high-fidelity gates, erasure conversion, and mid-circuit operations. A complementary encoding of information in electronic degrees of freedom using metastable fine-structure states has been proposed, similar to schemes used in ions. In contrast to nuclear spin states, which require a magnetic field for qubit splitting, fine-structure states have a natural frequency splitting on the terahertz scale. Although this makes state-insensitive trapping challenging, it is advantageous for state preparation and readout. Combining with existing optical and nuclear qubits, this fine-structure qubit can unlock the full potential of the level scheme, enabling new functionalities like optical qutrits, single-photon transitions to Rydberg states with fast qubit rotations, and mid-circuit readout operations. The researchers experimentally demonstrated core capabilities of a fine-structure qubit using Sr atoms trapped in an optical lattice. The qubit is encoded in the metastable triplet states |↑⟩ and |↓⟩, separated by about 17 THz. These states are coupled via a two-photon Raman transition through the triplet state |s⟩. They demonstrated fast two-photon Rabi oscillations with frequencies up to 2π×400 kHz and studied their decoherence mechanisms. They showed proof-of-principle read-out methods with about 96% detection efficiency for mid-circuit read-out. They also investigated the coherence of the fine-structure qubit with Ramsey and spin-echo measurements. The experimental setup involved loading about 10⁵ ⁸⁸Sr atoms into a 3D optical lattice. They performed resolved sideband cooling on the ¹S₀-³P₁ transition at