Quantum Metrology: Unlocking New Possibilities with Spin Squeezing, Structured Light, and More
In an exclusive interview with AZoQuantum, Dr. Mažena Mackoit-Sinkeviciene, a renowned physicist from Vilnius University, delves into the exciting world of quantum technologies and their real-world applications. She discusses her groundbreaking research, the Baltic Women in Science Fellowship, and the impact of her work on the field of quantum metrology.
The Baltic Women in Science Fellowship: A Recognition of Long-Term Impact
Dr. Mackoit-Sinkeviciene's work on quantum technologies has been recognized with the prestigious 2025 Baltic Women in Science Fellowship. She explains that her impact as a theoretical quantum physicist is not solely defined by a single experiment but by the theoretical frameworks she has developed. The jury was particularly impressed by her contributions to two distinct quantum platforms: solid-state quantum emitters and ultracold atomic systems.
One significant milestone was her research on point defects in diamond and hexagonal boron nitride as quantum emitters. By developing a microscopic theoretical model, she identified the carbon dimer defect as the source of ultraviolet quantum emission in hBN. This theoretical breakthrough was later experimentally confirmed in 2025 by multiple international groups, including researchers at CNRS Université de Montpellier. The delayed validation showcased the model's predictive power, guiding complex experimental efforts in quantum communication materials and their integration into quantum photonic platforms.
Another crucial aspect of her work is the development of analytically tractable and experimentally realistic models for spin squeezing in ultracold atomic gases. This approach has been recognized for its relevance to quantum-enhanced metrology and sensing.
Expanding Perspectives with Cross-Platform Research
Dr. Mackoit-Sinkeviciene's research has expanded her understanding of quantum technologies by bridging the gap between solid-state quantum emitters and ultracold atomic systems. This shift has allowed her to study how coherence control, noise mitigation, and Hamiltonian engineering operate across different physical platforms. It has also strengthened her appreciation for analytically tractable models that remain experimentally realistic.
Overcoming Metrological Limits with Spin Squeezing
Her work addresses the standard quantum limit in precision measurements, particularly in frequency metrology for advanced timekeeping. To surpass this limit, she develops spin-squeezing protocols based on engineered atom-light interactions in ultracold fermionic systems. A key innovation is the use of position-dependent laser phases and spin-orbit coupling to generate effective one-axis and two-axis twisting dynamics without strong intrinsic interactions. These strategies are compatible with existing cold-atom platforms and offer enhanced precision in optical clocks and quantum sensors.
Exploring the Power of Structured Light
Structured light, particularly beams with orbital angular momentum and spatially varying polarization, enables new light-matter coupling channels. Unlike plane waves, these fields imprint their spatial phase and polarization structure directly onto atomic coherence. Dr. Mackoit-Sinkeviciene's research explores phase-dependent dark states, orbital angular momentum exchange, and polarization-controlled transparency in atomic media.
These effects enable spatially resolved control of quantum states and open possibilities for high-dimensional quantum information encoding. By exploiting additional degrees of freedom, such as orbital angular momentum, frequency, and spatial modes, the approach transcends the conventional two-level qubit paradigm.
Extracting Weak Signals from Noisy Backgrounds
In a recent experiment, Dr. Mackoit-Sinkeviciene's group demonstrated their approach to extracting weak signals from noisy backgrounds. They generated spin squeezing in an atomic Fermi-Hubbard system using laser-induced coupling, aiming to reduce quantum noise below the shot-noise limit. By operating in the Mott-insulating regime and applying position-dependent laser coupling, they controlled one- and two-axis squeezing dynamics.
The key innovation is that they did not rely on amplification. Instead, they designed the dynamics to produce a predictable and robust signature of genuine many-body correlations, allowing them to distinguish these correlations from technical noise. This approach enables higher measurement precision without increasing the atom number, which is crucial for next-generation atomic clocks and quantum sensors.
Promising Applications and Technical Gaps
Dr. Mackoit-Sinkeviciene sees the most promising applications of her techniques in quantum-enhanced time-keeping and quantum interferometry. Spin-squeezed states directly improve phase and frequency sensitivity, benefiting optical atomic clocks and interferometric measurements. Enhanced clock stability also has implications for navigation and GPS-like systems.
Beyond clocks, these methods are relevant for precision interferometry and fundamental physics tests. Her recent review paper with international collaborators highlights the role of reduced quantum noise through squeezing in next-generation interferometric sensors.
Technical gaps toward deployable devices include extending coherence times, scalable and robust preparation of squeezed states, and integration into compact, stable platforms. Her work contributes by proposing experimentally feasible schemes compatible with existing cold-atom, clock, and interferometry architectures, bridging the gap between lab demonstrations and real-world quantum sensors.
Cross-Institutional Partnerships: Unlocking New Capabilities
International collaborations with experimental groups in Europe, the United States, and Australia have been vital to her progress. These partnerships ensured her theoretical work remained grounded in reality and directly influenced experimental design and interpretation. Interdisciplinary interactions between condensed matter physics, quantum optics, and atomic physics have also unlocked capabilities not accessible within a single subfield.
Accelerating Research and Community Building with the Award
Dr. Mackoit-Sinkeviciene plans to leverage the Baltic Women in Science Fellowship to accelerate her research agenda and strengthen the Baltic community's role in quantum science. The award will support deeper integration of her quantum metrology and quantum emitter work into European quantum research programs, enabling new collaborations and joint projects with leading groups.
She also aims to use the award for community building, connecting early-career researchers from the Baltic region to European quantum initiatives. Her career has been shaped by contributing to the quantum ecosystem in Lithuania, and she believes that long-term impact requires not only excellent research but also education, coordination, and international integration.
Dr. Mackoit-Sinkeviciene's passion for quantum science and her commitment to community building make her a valuable leader in the field. Her work continues to push the boundaries of quantum metrology, paving the way for exciting advancements in quantum technologies.
