Quantum and classical control of single photon states via a mechanical resonator

Optomechanical systems typically use light to control the quantum state of a mechanical resonator. In this paper, we propose a scheme for controlling the quantum state of light using the mechanical degree of freedom as a controlled beam splitter. Preparing the mechanical resonator in non-classical states enables an optomechanical Stern–Gerlach interferometer. When the mechanical resonator has a small coherent amplitude it acts as a quantum control, entangling the optical and mechanical degrees of freedom. As the coherent amplitude of the resonator increases, we recover single photon and two-photon interference via a classically controlled beam splitter. The visibility of the two-photon interference is particularly sensitive to coherent excitations in the mechanical resonator and this could form the basis of an optically transduced weak-force sensor

Phonon number measurements using single photon opto-mechanics

We describe a system composed of two coupled optical cavity modes with a coupling modulated by a bulk mechanical resonator. In addition, one of the cavity modes is irreversibly coupled to a single photon source. Our scheme is an opto-mechanical realisation of the Jaynes-Cummings model where the qubit is a dual rail optical qubit while the bosonic degree of freedom is a matter degree of freedom realised as the bulk mechanical excitation. We show the possibility of engineering phonon number states of the mechanical oscillator in such a system by computing the conditional state of the mechanics after successive photon counting measurements

Cost-effective analysis of the fractional flow reserve in an iranian cohort with multivessel coronary artery disease

Background: The fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) has proven effective in decreasing cardiac events by comparison with all-comers stenting. In this study, we aimed to evaluate the cost-effectiveness of this method in an Iranian population. Methods: In this prospective cohort, patients with moderate stenosis (50�70 severity) were included, while those with acute coronary syndrome were excluded. The patients were divided into 2 groups: the FFR group, for whom revascularization was performed based on FFR results, and the control group, for whom revascularization was performed based on the interventionist�s assessment. An FFR of less than 0.80 was considered ischemic in this investigation. Results: A total of 188 patients with moderate coronary artery lesions scheduled for elective PCI were included: 98 patients were assigned to the FFR group and 90 to the control group. Readmission and major adverse cardiac events (MACE) were decreased significantly in the FFR group (24.4 vs 11.2; P = 0.017 and 25.6 vs 12.2; P = 0.019, respectively). The quality-adjusted life-year (QALY) value was improved in the FFR group in comparison with the control group (0.8643 ± 0.0961 vs 0.7449 ± 0.10139, respectively; P < 0.001), resulting in a lower cost for each QALY in the FFR group than in the control group (131 395 349 QALY/rials vs 210 666 667 QALY/rials, respectively; P < 0.001). Additionally, our calculation of the incremental cost-effectiveness ratio showed that the cost-effectiveness of the FFR utilization was at least 409 million rials and at most 431 million rials for each QALY, depending on the inclusion of the cost of the FFR catheter. Conclusions: Our results demonstrated the effectiveness of FFR in diminishing MACE. The method was cost-effective according to various calculation methods in an Iranian population. (Iranian Heart Journal 2020; 21(3): 64-72). © 2020, Iranian Heart Association. All rights reserved