Researchers have developed a general design principle for creating and controlling exceptional points (EPs) in non-Hermitian quantum systems, utilizing momentum-space deformations. These EPs are a hallmark of quantum systems where the Hamiltonian is non-Hermitian, implying that time evolution does not conserve probability. The study identifies universal criteria for specific momentum sectors to host EPs and the corresponding critical deformation strengths. A remarkable finding is that a single momentum-sector EP can induce an exponential proliferation of many-body eigenvector coalescences.

The work also establishes EPs as a universal mechanism for purifying arbitrary mixed quantum states. Distinct purification regimes and a fundamental odd-even system-size dichotomy in the thermodynamic limit have been uncovered. This purification capability is crucial for the development of quantum technologies, as it allows obtaining pure states from initially mixed states, which is essential for the coherence and performance of quantum devices.

Furthermore, the proposed framework offers a systematic reverse-engineering protocol for generating short- and long-range, reciprocal and nonreciprocal non-Hermitian quantum matter, together with an explicit Lindblad embedding. This provides a unified route to exceptional-point engineering and the controlled design of many-body non-Hermitian quantum systems. The results open new avenues for manipulating and understanding quantum dynamics in non-conservative environments, with implications for quantum computing and materials science.