5 papers
Using an SU(3)/U(2) Wigner Function to Represent Noisy Spin Ensembles
Andrew Kolmer Forbes
The SU(2) Wigner function represents a quantum state of a spin- as a real-valued function on the surface of a 2-sphere. For an ensemble of spin-1/2 particles, this represent…
Fragility of Optimal Measurements due to Noise in Probe States for Quantum Sensing
Andrew Kolmer Forbes, Marco A. RodrÃguez-GarcÃa, Ivan H. Deutsch
For a given quantum state used in sensing, the quantum Cramér-Rao bound (QCRB) sets a fundamental limit on the precision achievable by an unbiased estimator of an unknown paramete…
Long-Range Interacting Many-Body Systems in the Irrep Basis
Ivy Pannier-Günther, Andrew Kolmer Forbes, Pablo M. Poggi +1
Spin models featuring infinite-range, homogeneous all-to-all interactions can be efficiently described due to the existence of a symmetry-restricted Hilbert subspace and an underly…
A Hybrid Measurement Scheme for Generating nonGaussian Spin States
Andrew Kolmer Forbes, Ivan H. Deutsch
We present a protocol for generating nonclassical states of atomic spin ensembles through the backaction induced by a hybrid measurement of light that is entangled with atoms, comb…
Modeling local decoherence of a spin ensemble using a generalized Holstein-Primakoff mapping to a bosonic mode
Andrew Kolmer Forbes, Philip Daniel Blocher, Ivan H. Deutsch
We show how the decoherence that occurs in an entangling atomic spin-light interface can be simply modeled as the dynamics of a bosonic mode. Although one seeks to control the coll…