Quantum information processing (QIP) and Quantum Simulation (QS) can potentially provide an exponential speedup for certain problems over the corresponding (known) algorithms on conventional computers. QIP makes use of the counter-intuitive properties of quantum mechanics, like entanglement and the superposition principle (being in more states than one simultaneously). On the way towards a useful QIP device these properties, mostly subject of thought experiments so far, will have to become a practical reality. I will discuss experiments towards Quantum Information Processing (QIP) and Quantum Simulation (QS) with trapped ions. Most requirements for QIP and QS have been demonstrated in this system, with two big challenges remaining: Improving operation fidelity and scaling up to larger numbers of qubits.
The architecture pursued at the Ion Storage Group at NIST is based on quantum information stored in long lived internal (hyperfine) states of the ions. We investigate the use of laser beams and microwave fields to induce both single-qubit rotations and multi-qubit gates mediated by the Coulomb interaction between ions. Moving ions through a multi-zone trap architecture allows for keeping the number of ions per zone small, while sympathetic cooling with a second ion species can remove energy and entropy from the system.
After a brief introduction to these elements, I will present the current status of experiments and some future perspectives for QIP and QS.
This work has been supported by IARPA, DARPA, ARO, ONR, and the NIST Quantum Information Program.