Quantum spin squeezing

J Ma, X Wang, CP Sun, F Nori - Physics Reports, 2011‏ - Elsevier
This paper reviews quantum spin squeezing, which characterizes the sensitivity of a state
with respect to SU (2) rotations, and is significant for both entanglement detection and high …

Dynamics of finite dimensional non-hermitian systems with indefinite metric

R Ramírez, M Reboiro - Journal of Mathematical Physics, 2019‏ - pubs.aip.org
We discuss the time evolution of physical finite dimensional systems which are modelled by
non-hermitian Hamiltonians. We address both general non-hermitian Hamiltonians and …

Exceptional Points from the Hamiltonian of a hybrid physical system: Squeezing and anti-Squeezing

R Ramírez, M Reboiro, D Tielas - The European Physical Journal D, 2020‏ - Springer
We study the appearance of Exceptional Points in a hybrid system composed of a
superconducting flux-qubit and an ensemble of nitrogen-vacancy colour centres in diamond …

Use of discrete Wigner functions in the study of decoherence of a system of superconducting flux-qubits

M Reboiro, O Civitarese, D Tielas - Physica Scripta, 2015‏ - iopscience.iop.org
The persistence of coherence of a system of superconducting flux-qubits, in the presence of
an ensemble of electrons, is analysed. The time evolution of the system is solved exactly …

Fast spin squeezing by distance-selective long-range interactions with Rydberg molecule dressing

H Wu, XY Lin, ZX Ding, SB Zheng… - Science China Physics …, 2022‏ - Springer
We propose a Rydberg molecule dressing scheme to create strong and long-ranged
interactions at selective distances. This is achieved through laser coupling ground-state …

Squeezing in a spin chain with site-dependent periodic and long-range interactions

O Civitarese, M Reboiro, L Rebon, D Tielas - Physics Letters A, 2010‏ - Elsevier
Numerical and analytical results for the squeezing factor, ζ2, in a pseudo-spin s-1/2 chain.
The open chain is composed by N two-level atoms with site-dependent interactions. The …

Use of discrete Wigner functions in the study of a hybrid dissipative system

M Reboiro, O Civitarese, R Ramirez, D Tielas - Physica Scripta, 2017‏ - iopscience.iop.org
The persistence of coherence in a hybrid dissipative system, which is composed of
superconducting flux-qubits (SFQs) and an electron ensemble, is analyzed. Both the …

Study of decoherence in a system of superconducting flux-qubits interacting with an ensemble of electrons

M Reboiro, O Civitarese, R Ramirez - Annals of Physics, 2017‏ - Elsevier
The degree of coherence in a hybrid system composed of superconducting flux-qubits and
an electron ensemble is analysed. Both, the interactions among the electrons and among …

Spin observables in an atomic CQE system

O Civitarese, M Reboiro, D Tielas - Journal of Physics B: Atomic …, 2013‏ - iopscience.iop.org
A cavity quantum electrodynamical Hamiltonian is solved to study spin observables, such as
the orientation and fluctuations of the total spin and entropy, in a system of N two-level atoms …

Nonclassical properties of coherent states and excited coherent states for continuous spectra

GR Honarasa, MK Tavassoly, M Hatami… - Journal of Physics A …, 2011‏ - iopscience.iop.org
Based on the definition of coherent states for continuous spectra and analogous to photon-
added coherent states for discrete spectra, we introduce the excited coherent states for …