The recent proliferation of NISQ devices has made it imperative to understand their power. In
this work, we define and study the complexity class NISQ, which encapsulates problems that …

While quantum state tomography is notoriously hard, most states hold little interest to
practically minded tomographers. Given that states and unitaries appearing in nature are of …

We develop a framework for learning properties of quantum states beyond the assumption of
independent and identically distributed (iid) input states. We prove that, given any learning …

In the problem of quantum channel certification, we have black box access to a quantum
process and would like to decide if this process matches some predefined specification or is …

Estimating the unitarity of an unknown quantum channel provides information on how much
it is unitary, which is a basic and important problem in quantum device certification and …

In this paper we revisit one of the prototypical tasks for characterizing the structure of noise
in quantum devices, estimating the eigenvalues of an $ n $-qubit Pauli noise channel. Prior …

In this paper, we propose a method for denoising experimental density matrices that
combines standard quantum state tomography with an attention-based neural network …

Given $ n $ copies of an unknown quantum state $\rho\in\mathbb {C}^{d\times d} $, quantum
state certification is the task of determining whether $\rho=\rho_0 $ or $\|\rho-\rho_0 …

We study the sample complexity of the prototypical tasks quantum purity estimation and
quantum inner product estimation. In purity estimation, we are to estimate $ tr (\rho^ 2) $ of …

We consider the classic question of state tomography: given copies of an unknown quantum
state ρ∈C^d*d, output ρ which is close to ρ in some sense, eg trace distance or fidelity …