790 research outputs found

    Coherent Optomechanical State Transfer between Disparate Mechanical Resonators

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    Hybrid quantum systems have been developed with various mechanical, optical and microwave harmonic oscillators. The coupling produces a rich library of interactions including two mode squeezing, swapping interactions, back-action evasion and thermal control. In a multimode mechanical system, coupling resonators of different scales (both in frequency and mass) leverages the advantages of each resonance. For example: a high frequency, easily manipulated resonator could be entangled with a low frequency massive object for tests of gravitational decoherence. Here we demonstrate coherent optomechanical state swapping between two spatially and frequency separated resonators with a mass ratio of 4. We find that, by using two laser beams far detuned from an optical cavity resonance, efficient state transfer is possible through a process very similar to STIRAP (Stimulated Raman Adiabatic Passage) in atomic physics. Although the demonstration is classical, the same technique can be used to generate entanglement between oscillators in the quantum regime

    Experimental exploration of the optomechanical attractor diagram and its dynamics

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    We demonstrate experimental exploration of the attractor diagram of an optomechanical system where the optical forces compensate for the mechanical losses. In this case stable self-induced oscillations occur but only for specific mirror amplitudes and laser detunings. We demonstrate that we can amplify the mechanical mode to an amplitude 500 times larger than the thermal amplitude at 300K. The lack of unstable or chaotic motion allows us to manipulate our system into a non-trivial steady state and explore the dynamics of self-induced oscillations in great detail.Comment: 6 pages, 4 figure

    Evaluation of Guidance and Counselling Programme in Two Colleges of Education in Upper West Region of Ghana

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    This study sought to examine the guidance and counselling programmes in the two Colleges’ of Education in the Upper West Region of Ghana. The study was carried out with the aim of offering some suggestions for the improvement of guidance and counselling programmes in both institutions. The research design for this study was a descriptive survey. The target population comprised one thousand and eighty-seven (1087) teacher trainees, two (2) co-ordinators and fifty-seven (57) tutors. The sample was made up of two-hundred and twenty (220) teacher trainees and thirty (30) tutor and co-ordinators with a total sample of two hundred and fifty (250) respondents from both colleges. The main instrument used was a questionnaire because it was the quickest means of collecting data from the respondents. Multiple sampling techniques comprising purposive sampling, proportional and simple random sampling methods were used. The data was analysed using descriptive statistical procedures with frequencies tables and percentages. The findings revealed that trainees were aware of the guidance and counselling services but lacked confidence in the programme and as a result did not regularly patronize them. The findings again showed that there were a lot of challenges confronting guidance and counselling programmes in both institutions that needed support for efficient and effective guidance programmes. It was therefore recommended that public education should be mounted regularly in sustainable basis to educate the teacher trainees, tutors and college authorities on the need for guidance and counseling programmes. Keywords: Apprenticeship, Attitude, Challenges, Competent, Implementation, Logistics, Programme, Training

    Series solution of the time-dependent Schr\"{o}dinger-Newton equations in the presence of dark energy via the Adomian Decomposition Method

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    The Schr\"{o}dinger-Newton model is a nonlinear system obtained by coupling the linear Schr\"{o}dinger equation of canonical quantum mechanics with the Poisson equation of Newtonian mechanics. In this paper we investigate the effects of dark energy on the time-dependent Schr\"{o}dinger-Newton equations by including a new source term with energy density ρΛ=Λc2/(8πG)\rho_{\Lambda} = \Lambda c^2/(8\pi G), where Λ\Lambda is the cosmological constant, in addition to the particle-mass source term ρm=mψ2\rho_m = m|\psi|^2. The resulting Schr\"{o}dinger-Newton-Λ\Lambda (S-N-Λ\Lambda) system cannot be solved exactly, in closed form, and one must resort to either numerical or semianalytical (i.e., series) solution methods. We apply the Adomian Decomposition Method, a very powerful method for solving a large class of nonlinear ordinary and partial differential equations, to obtain accurate series solutions of the S-N-Λ\Lambda system, for the first time. The dark energy dominated regime is also investigated in detail. We then compare our results to existing numerical solutions and analytical estimates, and show that they are consistent with previous findings. Finally, we outline the advantages of using the Adomian Decomposition Method, which allows accurate solutions of the S-N-Λ\Lambda system to be obtained quickly, even with minimal computational resources.Comment: 20 pages, 1 table, 8 figure

    Rancang Bangun Website Travel Request pada PT. Ids Medical System Indonesia

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    Travel atau dalam bahasa Indonesia adalah perjalanan, merupakan kegiatan jalan- jalan atau pun liburan. IDS Medical Systems Group (idsMED Group) adalah salah satu penyedia solusi terintegrasi terbesar untuk peralatan medis, perlengkapan dan layanan di Asia. Merancang dan membangun Website Travel Request dengan menggunakan bahasa pemrogramman PHP. Website Travel Request ini sudah berhasil dan dirancang dan dibangun untuk memenuhi kebutuhan user. Website Travel Request dibuat dengan sedemikian rupa agar dapat digunakan dengan mudah oleh user tanpa perlu pelatihan yang rumit. Maka dari itu diharapkan dengan adanya pembaharuan sistem Travel Request, kegiatan request perjalanan dapat dengan mudah dilakukan oleh user