Ortolano Giuseppe, Losero Elena, Pirandola Stefano, Genovese Marco, Ruo-Berchera Ivano
Quantum Metrology and Nano Technologies Division, INRiM, Strada delle Cacce 91, 10135 Torino, Italy.
DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
Sci Adv. 2021 Jan 20;7(4). doi: 10.1126/sciadv.abc7796. Print 2021 Jan.
The final goal of quantum hypothesis testing is to achieve quantum advantage over all possible classical strategies. In the protocol of quantum reading, this is achieved for information retrieval from an optical memory, whose generic cell stores a bit of information in two possible lossy channels. We show, theoretically and experimentally, that quantum advantage is obtained by practical photon-counting measurements combined with a simple maximum-likelihood decision. In particular, we show that this receiver combined with an entangled two-mode squeezed vacuum source is able to outperform any strategy based on statistical mixtures of coherent states for the same mean number of input photons. Our experimental findings demonstrate that quantum entanglement and simple optics are able to enhance the readout of digital data, paving the way to real applications of quantum reading and with potential applications for any other model that is based on the binary discrimination of bosonic loss.
量子假设检验的最终目标是在所有可能的经典策略之上实现量子优势。在量子读取协议中，对于从光学存储器进行信息检索而言，这一目标得以实现，该光学存储器的通用单元在两种可能的有损信道中存储一位信息。我们在理论和实验上均表明，通过实际的光子计数测量与简单的最大似然决策相结合可获得量子优势。特别地，我们表明，对于相同的平均输入光子数，这种接收器与纠缠双模压缩真空源相结合能够超越基于相干态统计混合的任何策略。我们的实验结果表明，量子纠缠和简单光学能够增强数字数据的读出，为量子读取的实际应用铺平道路，并为基于玻色子损耗二元判别法的任何其他模型带来潜在应用。
