Quantum Computation

Quantum Simulation of Interacting Fermions Lattice Models in Trapped Ions


J. Casanova, A. Mezzacapo, L. Lamata, and E. Solano


Submitted to Physical Review Letters (2011)

We propose a method of simulating many-body interacting fermion lattice models in trapped ions, including highly nonlinear interactions in arbitrary spatial dimensions and for arbitrarily distant couplings. We encode the products of fermionic operators in nonlocal spin operators of an ion string, which are efficiently implementable, while a Trotter expansion of the total evolution operator can be applied by using only polynomial resources.

Workshop on the Quantum Physics of Phase

2012-04-23 - 2012-04-26

The workshop aims to gather world leading experts on the physics and applications of quantum phenomena in microwave circuits at low temperatures. This will include the following topics:

- Quantum computation schemes and devices
- Circuit MASERS and parametric amplifiers
- Quantum limited measurement and squeezing
- Quantum phase slips and geometric phases
- Single charge pumping and quantum metrology
- Superconducting and electromechanical technologies
Sponsored by:

QIPC cluster review meeting

2012-04-18 - 2012-04-20
NH Hotel Bingen, Museumstrasse 3, D-55411 Bingen (Mainz) Germany

This is the traditional QIPC cluster reviews. The program is as follows:

Call For Conference Proposals published


A call for proposals for the next QUIE2T sponsored QIPC conference has been published.

A call for proposals for the next QUIE2T sponsored QIPC conference has been published.

Holonomic quantum computing in ground states of spin chains with symmetry-protected topological order


M. Renes, Akimasa Miyake, Gavin K. Brennen, and Stephen D. Bartlett



While solid-state devices offer naturally reliable hardware for modern classical computers, thus far quantum information processors resemble vacuum tube computers in being neither reliable nor scalable. Strongly correlated many body states stabilized in topologically ordered matter offer the possibility of naturally fault tolerant computing, but are both challenging to engineer and coherently control and cannot be easily adapted to different physical platforms.

Quantum Information Team, LTCI, Telecom ParisTech

Research Type: 

 - Quantum key distribution with continuous variables: theoretical and experimental work on long-distance system performance and side channel induced attacks

- Quantum cryptographic primitives: theoretical and experimental work on secret sharing, coin flipping, entanglement verification in the presence of adversaries

- Theory of Quantum Computation and Quantum Information including measurement-based quantum computing, entanglement theory and foundations of physics

Romain Alléaume, Eleni Diamanti, Damian Markham, Isabelle Zaquine

Prospects for fast Rydberg gates on an atom chip


M. M. Müller, H. R. Haakh, T. Calarco, C. P. Koch and C. Henkel


Quantum Inf. Process. 10, 771 (2011). From the issue entitled "Special Issue on Neutral Particles".

Atom chips are a promising candidate for a scalable architecture for quantum information processing provided a universal set of gates can be implemented with high fidelity. The difficult part in achieving universality is the entangling two-qubit gate. We consider a Rydberg phase gate for two atoms trapped on a chip and employ optimal control theory to find the shortest gate that still yields a reasonable gate error. Our parameters correspond to a situation where the Rydberg blockade regime is not yet reached.

Electric-field sensing using single diamond spins


F. Dolde, H. Fedder, M. Doherty, T. Nöbauer, F. Rempp, G. Balasubramanian, T. Wolf, F. Reinhard, L. Hollenberg, F. Jelezko, J. Wrachtrup


Nature Physics, 7 (2011), pp 459 - 463

The ability to sensitively detect individual charges under ambient conditions would benefit a wide range of applications across disciplines. However, most current techniques are limited to low-temperature methods such as single-electron transistors, single-electron electrostatic force microscopy and scanning tunnelling microscopy. Here we introduce a quantum-metrology technique demonstrating precision three-dimensional electric-field measurement using a single nitrogen-vacancy defect centre spin in diamond. An a.c.

Implementing the Quantum von Neumann Architecture with Superconducting Circuits


Matteo Mariantoni, H. Wang, T. Yamamoto, M. Neeley1, Radoslaw C. Bialczak, Y. Chen, M. Lenander, Erik Lucero, A. D. O’Connell, D. Sank, M. Weides, J. Wenner, Y. Yin, J. Zhao, A. N. Korotkov, A. N. Cleland, John M. Martinis


Science Vol. 334 no. 6052 pp. 61-65. DOI: 10.1126/science.1208517

The von Neumann architecture for a classical computer comprises a central processing unit and a memory holding instructions and data. We demonstrate a quantum central processing unit that exchanges data with a quantum random-access memory integrated on a chip, with instructions stored on a classical computer. We test our quantum machine by executing codes that involve seven quantum elements: Two superconducting qubits coupled through a quantum bus, two quantum memories, and two zeroing registers.

Atom Counting in Expanding Ultracold Clouds


S. Braungardt, M. Rodríguez, A. Sen De, U. Sen, M. Lewenstein



We study the counting statistics of ultracold bosonic atoms that are released from an optical lattice. We show that the counting probability distribution of the atoms collected at a detector located far away from the optical lattice can be used as a method to infer the properties of the initially trapped states. We consider initial superfluid and insulating states with different occupation patterns. We analyze how the correlations between the initially trapped modes that develop during the expansion in the gravitational field are reflected in the counting distribution.

Syndicate content