Juq-378 -

To address and read out the qubits, a thin silicon‑nitride waveguide network is patterned on the surface of the alloy, enabling evanescent coupling of microwave photons into the bulk. This hybrid photonic‑spin architecture eliminates the need for bulky cryogenic microwave cavities and opens the door to on‑chip quantum control.

Spacecraft demand materials that are both lightweight and radiation‑hard. JUQ‑378’s metallic backbone offers high tensile strength (≈ 500 MPa) and excellent thermal conductivity, while the embedded qubits act as self‑diagnostic sensors that monitor radiation‑induced lattice defects in real time. By correlating qubit decoherence spikes with cumulative dose, engineers can predict material fatigue and schedule maintenance before catastrophic failure. JUQ-378

Traditional solid‑state qubits—such as nitrogen‑vacancy (NV) centers in diamond or phosphorus donors in silicon—are isolated point defects that are deliberately spaced far apart to avoid unwanted dipolar interactions. JUQ‑378 departs from this paradigm by densely embedding a lattice of transition‑metal ions (Mn(^2+)) within a copper‑based body‑centered cubic (BCC) host. To address and read out the qubits, a

Key to this design is the exploitation of symmetry‑protected decoherence‑free subspaces. The BCC lattice provides a highly isotropic magnetic environment, while the Mn(^2+) ions (high‑spin d⁵ configuration) experience a near‑zero crystal‑field splitting, allowing their electron spin (S = 5/2) to act as a multi‑level qudit. By tuning the Mn concentration to 0.2 at % and employing isotopic purification of Cu (⁶³Cu, ⁶⁵Cu) to suppress nuclear spin noise, the team achieved T(_2) coherence times exceeding 1 ms at 77 K—a record for a bulk metallic system. Spacecraft demand materials that are both lightweight and

The Mn‑based spin qubits have a large magnetic moment (5 µ(_B)), making them exceptionally sensitive to local magnetic field fluctuations. When operated in a spin‑echo protocol, JUQ‑378 can achieve magnetic field sensitivities of 10 pT Hz(^-½) at 77 K, surpassing NV‑diamond sensors at room temperature. This performance, combined with the alloy’s mechanical durability, enables embedded magnetometers in aerospace structures (e.g., wing skins) and high‑precision gyroscopes for autonomous navigation.