Details
| Original language | English |
|---|---|
| Article number | 013027 |
| Journal | New Journal of Physics |
| Volume | 19 |
| Issue number | 1 |
| Publication status | Published - 20 Jan 2017 |
Abstract
We present criteria to detect the depth of entanglement in macroscopic ensembles of spin-j particles using the variance and second moments of the collective spin components. The class of states detected goes beyond traditional spin-squeezed states by including Dicke states and other unpolarized states. The criteria derived are easy to evaluate numerically even for systems of very many particles and outperform past approaches, especially in practical situations where noise is present. We also derive analytic lower bounds based on the linearization of our criteria, which make it possible to define spin-squeezing parameters for Dicke states. In addition, we obtain spin squeezing parameters also from the condition derived in (Sørensen and Mølmer 2001 Phys. Rev. Lett. 86 4431). We also extend our results to systems with fluctuating number of particles.
Keywords
- Dicke states, entanglement detection, quantum entanglement, spin squeezing
ASJC Scopus subject areas
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In: New Journal of Physics, Vol. 19, No. 1, 013027, 20.01.2017.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Entanglement and extreme spin squeezing of unpolarized states
AU - Vitagliano, Giuseppe
AU - Apellaniz, Iagoba
AU - Kleinmann, Matthias
AU - Lücke, Bernd
AU - Klempt, Carsten
AU - Tóth, Géza
PY - 2017/1/20
Y1 - 2017/1/20
N2 - We present criteria to detect the depth of entanglement in macroscopic ensembles of spin-j particles using the variance and second moments of the collective spin components. The class of states detected goes beyond traditional spin-squeezed states by including Dicke states and other unpolarized states. The criteria derived are easy to evaluate numerically even for systems of very many particles and outperform past approaches, especially in practical situations where noise is present. We also derive analytic lower bounds based on the linearization of our criteria, which make it possible to define spin-squeezing parameters for Dicke states. In addition, we obtain spin squeezing parameters also from the condition derived in (Sørensen and Mølmer 2001 Phys. Rev. Lett. 86 4431). We also extend our results to systems with fluctuating number of particles.
AB - We present criteria to detect the depth of entanglement in macroscopic ensembles of spin-j particles using the variance and second moments of the collective spin components. The class of states detected goes beyond traditional spin-squeezed states by including Dicke states and other unpolarized states. The criteria derived are easy to evaluate numerically even for systems of very many particles and outperform past approaches, especially in practical situations where noise is present. We also derive analytic lower bounds based on the linearization of our criteria, which make it possible to define spin-squeezing parameters for Dicke states. In addition, we obtain spin squeezing parameters also from the condition derived in (Sørensen and Mølmer 2001 Phys. Rev. Lett. 86 4431). We also extend our results to systems with fluctuating number of particles.
KW - Dicke states
KW - entanglement detection
KW - quantum entanglement
KW - spin squeezing
UR - http://www.scopus.com/inward/record.url?scp=85011409884&partnerID=8YFLogxK
U2 - 10.1088/1367-2630/19/1/013027
DO - 10.1088/1367-2630/19/1/013027
M3 - Article
AN - SCOPUS:85011409884
VL - 19
JO - New Journal of Physics
JF - New Journal of Physics
SN - 1367-2630
IS - 1
M1 - 013027
ER -