Ramsey interferometry with generalized one-axis twisting echoes

authored by
Marius Schulte, Victor J. Martínez-Lahuerta, Maja S. Scharnagl, Klemens Hammerer
Abstract

We consider a large class of Ramsey interferometry protocols which are enhanced by squeezing and un-squeezing operations before and after a phase signal is imprinted on the collective spin of N particles. We report an analytical optimization for any given particle number and strengths of (un-)squeezing. These results can be applied even when experimentally relevant decoherence processes during the squeezing and un-squeezing interactions are included. Noise between the two interactions is however not considered in this work. This provides a generalized characterization of squeezing echo protocols, recovering a number of known quantum metrological protocols as local sensitivity maxima, thereby proving their optimality. We discover a single new protocol. Its sensitivity enhancement relies on a double inversion of squeezing. In the general class of echo protocols, the newly found over-un-twisting protocol is singled out due to its Heisenberg scaling even at strong collective dephasing.

Organisation(s)
QuantumFrontiers
CRC 1227 Designed Quantum States of Matter (DQ-mat)
Institute of Theoretical Physics
Institute of Gravitation Physics
External Organisation(s)
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Type
Article
Journal
Quantum
Volume
4
Pages
268-286
No. of pages
19
ISSN
2521-327X
Publication date
15.05.2020
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Atomic and Molecular Physics, and Optics, Physics and Astronomy (miscellaneous)
Electronic version(s)
https://doi.org/10.48550/arXiv.1911.11801 (Access: Open)
https://doi.org/10.22331/q-2020-05-15-268 (Access: Open)
https://doi.org/10.15488/9960 (Access: Open)