TY  - JOUR
A1  - Müller, Matthias M.
A1  - Haakh, Harald R.
A1  - Calarco, Tommaso
A1  - Koch, Christiane P.
A1  - Henkel, Carsten
T1  - Prospects for fast Rydberg gates on an atom chip
JF  - Quantum information processing
N2  - 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. We discuss the role of spontaneous emission and the effect of noise from the chip surface on the atoms in the Rydberg state.
KW  - Optimal control
KW  - Phase gate
KW  - Rydberg atoms
KW  - Cavity quantum electrodynamics
Y1  - 2011
U6  - https://doi.org/10.1007/s11128-011-0296-0
SN  - 1570-0755
VL  - 10
IS  - 6
SP  - 771
EP  - 792
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Haakh, Harald R.
A1  - Intravaia, Francesco
T1  - Mode structure and polaritonic contributions to the Casimir effect in a magnetodielectric cavity
JF  - Physical review : A, Atomic, molecular, and optical physics
N2  - We present a full analysis of the mode spectrum in a cavity formed by two parallel plates, one of which is magnetodielectric (metamaterial) while the other one is metallic, and obtain dispersion relations in closed form. The optical properties of the cavity walls are described in terms of realistic models for effective permittivity and permeability. Surface polaritons, i.e., electromagnetic modes that have at least partly an evanescent character, are shown to dominate the Casimir interaction at small separations. We analyze in detail the s-polarized polaritons, which are a characteristic feature of a magnetodielectric configuration, and discuss their role in the repulsive Casimir force.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevA.88.052503
SN  - 1050-2947
SN  - 1094-1622
VL  - 88
IS  - 5
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Haakh, Harald R.
A1  - Henkel, Carsten
A1  - Spagnolo, Salvatore
A1  - Rizzuto, Lucia
A1  - Passante, Roberto
T1  - Dynamical Casimir-Polder interaction between an atom and surface plasmons
JF  - Physical review : A, Atomic, molecular, and optical physics
N2  - We investigate the time-dependent Casimir-Polder potential of a polarizable two-level atom placed near a surface of arbitrary material, after a sudden change in the parameters of the system. Different initial conditions are taken into account. For an initially bare ground-state atom, the time-dependent Casimir-Polder energy reveals how the atom is "being dressed" by virtual, matter-assisted photons. We also study the transient behavior of the Casimir-Polder interaction between the atom and the surface starting from a partially dressed state, after an externally induced change in the atomic level structure or transition dipoles. The Heisenberg equations are solved through an iterative technique for both atomic and field operators in the medium-assisted electromagnetic field quantization scheme. We analyze, in particular, how the time evolution of the interaction energy depends on the optical properties of the surface, in particular on the dispersion relation of surface plasmon polaritons. The physical significance and the limits of validity of the obtained results are discussed in detail.
Y1  - 2014
U6  - https://doi.org/10.1103/PhysRevA.89.022509
SN  - 1050-2947
SN  - 1094-1622
VL  - 89
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  -