Improvement in quantum communication using quantum switch

Abstract

Applications of the quantum switch on quantum channels have recently become a topic of intense discussion. In the present work, we show that some useless (for communication) channels may provide useful communication under the action of quantum switch for several information-theoretic tasks: quantum random access codes, quantum steering, etc. We demonstrate that the quantum switch can also be useful in preventing the loss of coherence in a system when only coherence-breaking channels are the available channels for communication. We also show that if a useless quantum channel does not provide useful communication even after using a quantum switch, concatenating the channel with another suitable quantum channel, and subsequently using the switch, one may achieve useful communication. Finally, we discuss how the introduction of noise in the quantum switch can reduce the advantage that the switch provides.

Magnon-magnon entanglement generation between two remote interaction-free optomagnonic systems via optical Bell-state measurement

“…Hybrid quantum systems are flexible platforms that enable the combination of distinct physical systems with complementary characteristics [1][2][3][4][5][6][7][8]. In particular, the hybrid magnonic systems are highly promising for many short-and long-term applications in quantum technologies, including quantum sensing [9], quantum communication [10,11], quantum teleportation [12,13], quantum simulation [14,15],quantum information [16,17] and quantum computing [18][19][20]. In addition, hybrid magnonics enables an excellent protocol for the generation and manipulation of macroscopic quantum states.…”