Creation of quantum coherence with general measurement processes

Abstract

Quantum measurement not only can destroy coherence but also can create it. Here, we estimate the maximum amount of coherence, one can create under a complete non-selective measurement process. For our analysis, we consider projective as well as POVM measurements. Based on our observations, we characterize the measurement processes into two categories, namely, the measurements with the ability to induce coherence and the ones without this ability. Our findings also suggest that the more POVM elements present in a measurement that acts on the quantum system, the less will be its coherence creating ability. We also introduce the notion of raw coherence in the POVMs that helps to create quantum coherence. Finally, we find a trade-off relation between the coherence creation, entanglement generation between system and apparatus, and the mixedness of the system in a general measurement setup.

8 pages, 4 figures, updated manuscript, and one new author, Gautam Sharma, added

References in corpus (6)

• Linking Quantum Discord to Entanglement in a Measurement
• All non-classical correlations can be activated into distillable entanglement
• Max- relative entropy of coherence: an operational coherence measure
• Translation of Lueders' "Uber die Zustandsanderung durch den Messprozess"
• Uncertainty Relations for Quantum Coherence
• Impossibility of creating a superposition of unknown quantum states