Semidefinite programs are convex optimization problems involving a linear objective
function and a domain of positive-semidefinite matrices. Over the past two decades, they …

Bell's 1964 theorem, which states that the predictions of quantum theory cannot be
accounted for by any local theory, represents one of the most profound developments in the …

The concept of randomness plays an important part in many disciplines. On the one hand,
the question of whether random processes exist is fundamental for our understanding of …

Quantum state discrimination underlies various applications in quantum information
processing tasks. It essentially describes the distinguishability of quantum systems in …

Quantum superposition of high-dimensional states enables both computational speed-up
and security in cryptographic protocols. However, the exponential complexity of tomographic …

By testing nonlocality, the security of entanglement-based quantum key distribution (QKD)
can be enhanced to being “device-independent.” Here we ask whether such a strong form of …

Random numbers are central to cryptography and various other tasks. The intrinsic
probabilistic nature of quantum mechanics has allowed us to construct a large number of …

The goal of self-testing is to characterize an a priori unknown quantum system based solely
on measurement statistics, ie, using an uncharacterized measurement device. Here we …

Dense coding is the seminal example of how entanglement can boost qubit communication,
from sending one bit to sending two bits. This is made possible by projecting separate …

The secure transfer of information is an important problem in modern telecommunications.
Quantum key distribution (QKD) provides a solution to this problem by using individual …