Physicists find that entanglement concentration is irreversible, in contrast with previous research

Several different types of entangled states can be used in quantum information processes, and these states can be converted into one another using a variety of conversion processes. While previous research has suggested that one of the most common types of conversions, called entanglement concentration, is reversible, a new paper shows for the first time that it is irreversible due to a trade-off relation between performance and reversibility. The finding could have implications for future developments in quantum information applications.

The physicists, Wataru Kumagai at Tohoku University in Sendai, Japan, and Nagoya University in Nagoya, Japan; and Masahito Hayashi at Nagoya University and the National University of Singapore, have published their paper on the irreversibility of entanglement concentration in a recent issue of Physical Review Letters.