Prospects of quantum information processing with atoms

Abstract

Quantum information, and particular questions of implementing quantum information processing, is now almost two decades old, and has developed into a mature field of physics. In the first decade many of the conceptual foundations of the field of quantum information were laid down, many of the basic theoretical proposals for implementing quantum computing and quantum communications with various physical systems were formulated, and a first generation of experimental demonstrations of some of the basic building blocks and protocols of QIPC were shown in the lab. Today we are in a phase where the experimental challenge is not only to achieve high fidelity in operations, but to scale up systems both in the number of qubits and in the complexity of the quantum operations towards fault tolerant quantum computing. Progress during the last few years has been remarkable, and exceeded our early dreams, although on the scale of futuristic goals and hopes of QIPC this remains a first step. The requirements of implementing QIPC include the manipulation of many particle quantum systems on the level of single quanta, the ability to prepare and read out quantum states with high fidelity, while achieving complete isolation from the environment. Quantum optical systems of trapped ions, atoms, molecules and photons, as in CQED, have always had a leading role in achieving these goals. The rapid progress in achieving quantum control in many particle physics happens, of course, in a much broader context, and solid state systems such as superconducting qubits, quantum dots and NV centers, as well as circuit QED and nanomechanics are becoming serious contenders for atomic systems. The present issue focuses on quantum information processing with neutral atoms and molecules. What do we see as interesting future directions and possibilities?