Keyring models: An Approach to Steerability

Published

February 6, 2018

Author(s)

Carl A. Miller, Roger Colbeck, Yaoyun Shi

Abstract

If a measurement is made on one half of a bipartite system then, conditioned on the outcome, the other half achieves a new reduced state. If these reduced states defy classical explanation -- that is, if shared randomness cannot produce these reduced states for all possible measurements -- the bipartite state is said to be steerable. Classifying the steerability of states is a challenging problem even for low dimensions. In the case of two-qubit systems a criterion is known for T-states (that is, 2-qubit states that have a maximally mixed marginal on the first subsystem) under projective measurements. In the current work we introduce the concept of keychain models -- a special class of local hidden state models -- which allows us to study steerability outside the set of T-states. We use keychain models to give a complete classification steering within the set of partially entangled Werner states. We also give a partial classification of steering for states that arise from applying uniform noise to pure two-qubit states.

Citation

Journal of Mathematical Physics

Volume

59

Issue

2

Pub Type

Journals

Download Paper

https://doi.org/10.1063/1.5006199

Local Download

Keywords

nonlocality, entanglement

Citation

Miller, C. , Colbeck, R. and Shi, Y. (2018), Keyring models: An Approach to Steerability, Journal of Mathematical Physics, [online], https://doi.org/10.1063/1.5006199 (Accessed October 9, 2025)