Noiseless linear amplification （NLA）, first proposed by Ralpha et al., is a nondeterministic amplification process which gives gain to the Fock state ｜n） → gn｜n）, with g being the amplification gain. We here gi...Noiseless linear amplification （NLA）, first proposed by Ralpha et al., is a nondeterministic amplification process which gives gain to the Fock state ｜n） → gn｜n）, with g being the amplification gain. We here give a general frame- work for improving the NLA scheme with arbitrary general local unitary operations. We derive the improvement in the amplification gain in 0 1 photon subspace. In particular, we study if the local unitary is composed of sin- gle mode squeezing and coherent displacement operation. Finally, numerical simulations show that local unitary operation could give a further enhancement in the amplification gain as well as the success probability, making the NLA more feasible in future optic quantum communications.展开更多
Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first...Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first demonstrate noise immunity enhancement by using phase-sensitive amplifier(PSA)with measurement-based noiseless linear amplifier(MB-NLA).We explore the signal transfer capability with the amplifier in a noisy channel.The MB-NLA enhanced PSA has obvious suppression effect on channel noises,especially it has improvement for the noise contaminated signal.Better performance can be achieved by flexibly adjusting amplifier parameters.With the amplifier,it is promising to overcome the entanglement-distribution loss and show its superiority in squeezing based quantum sensing.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11304013,11204197,11204379 and 11074244the National Basic Research Program of China under Grant No 2011CBA00200+1 种基金the Doctor Science Research Foundation of Ministry of Education of China under Grant No 20113402110059Civil Aerospace 2013669
文摘Noiseless linear amplification （NLA）, first proposed by Ralpha et al., is a nondeterministic amplification process which gives gain to the Fock state ｜n） → gn｜n）, with g being the amplification gain. We here give a general frame- work for improving the NLA scheme with arbitrary general local unitary operations. We derive the improvement in the amplification gain in 0 1 photon subspace. In particular, we study if the local unitary is composed of sin- gle mode squeezing and coherent displacement operation. Finally, numerical simulations show that local unitary operation could give a further enhancement in the amplification gain as well as the success probability, making the NLA more feasible in future optic quantum communications.
基金the National Natural Science Foundation of China(Grant No.12074233)the National Key Research and Development Program of China(Grant No.2021YFC2201802)Shanxi(1331 Project)。
文摘Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first demonstrate noise immunity enhancement by using phase-sensitive amplifier(PSA)with measurement-based noiseless linear amplifier(MB-NLA).We explore the signal transfer capability with the amplifier in a noisy channel.The MB-NLA enhanced PSA has obvious suppression effect on channel noises,especially it has improvement for the noise contaminated signal.Better performance can be achieved by flexibly adjusting amplifier parameters.With the amplifier,it is promising to overcome the entanglement-distribution loss and show its superiority in squeezing based quantum sensing.
