A field-by-field archive of research questions that still need answers.
Open problems, grouped by the same fields as the paper archive.
Papers show what has been done. Open problems show what is still unresolved.
The goal is to keep both in the same product.
Open problems by field.
Starting with a curated quantum source.
A curated quantum list drawn from IQOQI Vienna’s Open Quantum Problems archive, spanning foundations, entanglement theory, communication, computation, complexity, thermodynamics, cryptography, and adjacent quantum-information questions.
IQOQI Vienna · Open Quantum ProblemsA foundational problem about classifying Bell inequalities and understanding the full boundary between classical and quantum correlations.
An entanglement-theory question asking whether every undistillable state must necessarily have positive partial transpose.
A request for a clearer or closed-form characterization of relative entropy of entanglement in qubit settings.
A foundations problem probing whether vacuum correlations at long range can be captured or constrained through Bell-type inequalities.
A quantum-information problem about the existence and construction of mutually unbiased bases in unresolved dimensions.
A quantum-computing challenge around identifying error models that remain genuinely hard for fault-tolerant architectures to handle.
An entanglement problem asking how much can be inferred about separability or entanglement from spectral data alone.
A computation problem about the resources required to prepare product-structured quantum states or decompositions.
An entanglement-theory problem on when entanglement transformations can be made reversible under reasonable operational constraints.
A major measurement-theory problem on the existence and structure of symmetric informationally complete POVMs in all dimensions.
A communication problem asking whether every entangled state can in principle yield secret key under suitable protocols.
An entanglement question about which entanglement measures can change dramatically under the loss of a small subsystem.
A foundations problem on identifying Bell inequalities that remain valid across the entire quantum state space.
A nonlocality problem on what CGLMP inequalities really certify and how strong they are compared with other Bell witnesses.
An entanglement problem aimed at understanding or explicitly characterizing formation costs in Gaussian-state settings.
A communication problem about optimal or near-optimal single-copy measurement strategies for geometrically uniform ensembles.
A broad foundations entry collecting unresolved structural and operational questions around Bell inequalities and nonlocality.
A foundations problem about the shape, extremal structure, and constraints of the quantum nonlocal set.
A computation and many-body problem on when absolutely maximally entangled states exist for given system sizes and local dimensions.
A foundations problem exploring how decoherence functionals behave under composition and whether composition preserves physicality.
A communication and entanglement problem asking whether composing PPT channels always produces an entanglement-breaking channel.
An entanglement and steering problem on characterizing steering limits for qubits under general POVM measurements.
A many-body and information-theory problem tied to stronger refinements or extensions of the Bessis-Moussa-Villani conjecture.
An entanglement problem asking for a complete picture of rank inequalities governing quadripartite reduced states.
A foundations problem about what reversible dynamics are possible once systems are composed under generalized physical principles.
A foundations problem on whether causally well-behaved processes always admit purification in a larger theory.
A quantum complexity problem asking for the true computational complexity of deciding whether a bipartite mixed state is separable or far from separable.
A complexity-theory problem on whether single-prover protocols can verify quantum computations with strong guarantees and realistic assumptions.
A thermodynamics problem about whether Gibbs-preserving maps always admit a physically meaningful thermodynamic realization.
A quantum-cryptography problem asking whether classical secret correlations can exist in a bound form that cannot be distilled into key.
A recent cryptography and quantum-networking problem about the entanglement resources required for constrained routing tasks.