arXiv subjects

Z. Kis

Publications and source records attributed to Z. Kis.

6 recordsLinked to original sources

arXiv2010

Homogeneous linewidth of the I_11/2--I_15/2 optical transition of erbium in LiNbO_3:Er^3+

We work out a simple, pulsed pump-probe measurement scheme to measure the homogeneous linewidth of an atomic transition in an inhomogeneously broadened spectral line in a solid state environment. We apply the theory to the I_11/2 -- I_15/2 optical transition of erbium in LiNbO_3:Er^3+ crystal. Beside obtaining the homogeneous linewidth, we have estimated the population relaxation time as well.

physics.atom-ph↗

arXiv2005

Continuous variable remote state preparation

We extend exact deterministic remote state preparation (RSP) with minimal classical communication to quantum systems of continuous variables. We show that, in principle, it is possible to remotely prepare states of an ensemble that is parameterized by infinitely many real numbers, i.e., by a real function, while the classical communication cost is one real number only. We demonstrate continuous variable RSP in three examples using (i) quadrature measurement and phase space displacement operations, (ii) measurement of the optical phase and unitaries shifting the same, and (iii) photon counting and photon number shift.

quant-ph↗

arXiv2003

Arbitrary rotation and entanglement of flux SQUID qubits

We propose a new approach for the arbitrary rotation of a three-level SQUID qubit and describe a new strategy for the creation of coherence transfer and entangled states between two three-level SQUID qubits. The former is succeeded by exploring the coupled-uncoupled states of the system when irradiated with two microwave pulses, and the latter is succeeded by placing the SQUID qubits into a microwave cavity and used adiabatic passage methods for their manipulation.

quant-ph↗

arXiv2003

Measuring the Density Matrix by Local Addressing

We introduce a procedure to measure the density matrix of a material system. The density matrix is addressed locally in this scheme by applying a sequence of delayed light pulses. The procedure is based on the stimulated Raman adiabatic passage (STIRAP) technique. It is shown that a series of population measurements on the target state of the population transfer process yields unambiguous information about the populations and coherences of the addressed states, which therefore can be determined.

quant-ph↗

arXiv2003

Qubit Rotation by STIRAP

We introduce a novel procedure for qubit rotation, alternative to the commonly used method of Rabi oscillations of controlled pulse area. It is based on the technique of Stimulated Raman Adiabatic Passage (STIRAP) and therefore it is robust against fluctuations of experimental parameters. Furthermore, our work shows that it is in principle possible to perform quantum logic operations via stimulated Raman adiabatic passage. This opens up the search for a completely new class of schemes to implement logic gates.

quant-ph↗

arXiv2003

Enhanced Nonlinear Generation in a Three-Level Medium with Spatially Dependent Coherence

We consider a method for efficient parametric generation of a laser pulse. A single laser field is injected to a three-level medium which has two lower states and one excited state. The lower states are prepared initially in a position-dependent coherent superposition state. It is shown that by proper choice of the position dependence of the superposition along the direction of propagation, the incoming field can be converted completely to a new field.

quant-ph↗