Fifty years of developments in nuclear magnetic resonance (NMR) have resulted in an
unrivaled degree of control of the dynamics of coupled two-level quantum systems. This …

Quantum computers [1–4] are explicitly quantum mechanical systems that use phenomena
such as superposition and entanglement to perform computational tasks more efficiently …

This Letter presents a simple formula for the average fidelity between a unitary quantum
gate and a general quantum operation on a qudit, generalizing the formula for qubits found …

Because of its geometric nature, holonomic quantum computation is fault tolerant against
certain types of control errors. Although proposed more than a decade ago, the experimental …

We develop the concept of a unitary t-design as a means of expressing operationally useful
subsets of the stochastic properties of the uniform (Haar) measure on the unitary group U (2 …

We present an experimental implementation of the coined discrete-time quantum walk on a
square using a three-qubit liquid-state nuclear-magnetic-resonance (NMR) quantum …

We present a derivation and numerous applications of a compact explicit formula for the
average fidelity of a quantum operation on a finite-dimensional quantum system. The …

A major goal of develo** high-precision control of many-body quantum systems is to
realize their potential as quantum computers. A substantial obstacle to this is the extreme …

Lee-Yang zeros are points on the complex plane of physical parameters where the partition
function of a system vanishes and hence the free energy diverges. Lee-Yang zeros are …

We describe the use of composite rotations to combat systematic errors in single-qubit
quantum logic gates and discuss three families of composite rotations which can be used to …