Date:

2016-06-07

Reference:

Science 345, 302 (2014)

The construction of a quantum computer remains a fundamental scientific and technological challenge because of the influence of unavoidable noise. Quantum states and operations can be protected from errors through the use of protocols for quantum computing with faulty components. We present a quantum error-correcting code in which one qubit is encoded in entangled states distributed over seven trapped-ion qubits. The code can detect one bit flip error, one phase flip error, or a combined error of both, regardless on which of the qubits they occur.

Date:

2016-06-07

Reference:

Nature 511, 202 (2014)

The key to explaining and controlling a range of quantum phenomena is to study how information propagates around many-body systems. Quantum dynamics can be described by particle-like carriers of information that emerge in the collective behaviour of the underlying system, the so-called quasiparticles1.

Date:

2015-05-22

Reference:

New J. Phys. 17 053032

We propose a set of techniques that enable universal quantum computing to be carried out using dressed states. This applies in particular to the effort of realizing quantum computation in trapped ions using long-wavelength radiation, where coupling enhancement is achieved by means of static magnetic-field gradient.

Date:

2014-07-09

Reference:

New J. Phys. 16, 075007 (2014)

http://dx.doi.org/10.1088/1367-2630/16/7/075007

Date:

2014-10-15

Reference:

Phys. Rev. B 90, 155426 (2014)

http://dx.doi.org/10.1103/PhysRevB.90.155426

We study the properties of a quantum particle interacting with a one-dimensional structure of equidistant scattering centers. We derive an analytical expression for the dispersion relation and for the Bloch functions in the presence of both even and odd scattering waves within the pseudopotential approximation. This generalizes the well-known solid-state physics textbook result known as the Kronig-Penney model.

Date:

2015-05-26

Reference:

arXiv:1503.02312

Can high energy physics can be simulated by low-energy, nonrelativistic, many-body systems, such as ultracold atoms?

Date:

2014-01-21 - 2014-01-22

Reference:

ArXiv:1401:5387

The key to explaining a wide range of quantum phenomena is understanding how entanglement propagates around many-body systems. Furthermore, the controlled distribution of entanglement is of fundamental importance for quantum communication and computation. In many situations, quasiparticles are the carriers of information around a quantum system and are expected to distribute entanglement in a fashion determined by the system interactions.

Date:

2013-02-04

Reference:

arXiv:1302.0701v1

We present evidence for the existence of Majorana edge states in a number conserving theory describing a system of spinless fermions on two wires that are coupled by a pair hopping. Our analysis is based on the combination of a qualitative low energy approach and numerical techniques using the Density Matrix Renormalization Group.

Date:

2013-02-14

Reference:

URL: http://link.aps.org/doi/10.1103/PhysRevLett.110.070403

DOI: 10.1103/PhysRevLett.110.070403

PACS: 03.65.Ta, 03.67.Pp, 37.10.Ty

In general, a quantum measurement yields an undetermined answer and alters the system to be consistent with the measurement result. This process maps multiple initial states into a single state and thus cannot be reversed. This has important implications in quantum information processing, where errors can be interpreted as measurements.

Date:

2013-02-05

Reference:

URL: http://link.aps.org/doi/10.1103/PhysRevLett.110.060403

DOI: 10.1103/PhysRevLett.110.060403

PACS: 03.65.Wj, 03.67.Ac

We report on the implementation of a quantum process tomography technique known as direct characterization of quantum dynamics applied on coherent and incoherent single-qubit processes in a system of trapped