Quantumness and Entanglement Witnesses
  We analyze the recently introduced notion of quantumness witness and compare it to that of entanglement witness. We show that any entanglement witness is also a quantumness witness. We then consider some physically relevant examples and explicitly construct some witnesses. 
Paolo Facchi, Saverio Pascazio, Vlatko Vedral, Kazuya Yuasa
math-ph math.MP quant-ph