As quantum systems grow in size and complexity, verifying large-scale entangled states has become a central challenge for reliable quantum information processing. While full quantum state tomography provides the most complete characterization of a quantum state, it suffers from exponential scaling in both experimental effort and computational post-processing, rendering it impractical beyond modest system sizes.

Alternative strategies—such as entanglement witnesses or compressed sensing—alleviate some of the burden but often still require a large number of state copies to reach statistically significant conclusions. This limits their applicability in the large-scale regime.

Our Research Program

To address these limitations, our group develops a suite of scalable verification and tomography techniques tailored for realistic experimental scenarios, where resources are inherently constrained. These include:

• Few-copy and single-copy entanglement detection
  Efficient entanglement verification with minimal experimental repetitions [VQ1-VQ2]
• Sample-efficient and device-independent state certification
  Robust validation and certification of quantum states without requiring trust in the measurement devices [VQ3]
• Selective and partial quantum tomography
  Targeted reconstruction methods focused on specific observables or subsystems [VQ4-VQ5]
• Post-processing optimization
  Enhancement of tomographic reconstruction through optimized estimators and inference techniques [VQ6]

These methods combine tools from quantum information theory, probabilistic modeling, and variational optimization to make quantum verification and tomography feasible even in systems with arbitrary Hilbert space dimension. Together, they form a robust foundation for scalable and reliable quantum technologies.

Selected Publications

[VQ1] V. Saggio et al., Experimental Few-Copy Multi-Particle Entanglement Detection,
Nature Physics 15, 935 (2019)
https://doi.org/10.1038/s41567-019-0550-4

[VQ2] A. Dimić & B. Dakić, Single-Copy Entanglement Detection,
npj Quantum Information 4, 11 (2018)
https://doi.org/10.1038/s41534-017-0055-x