892 research outputs found
Coherent Optomechanical State Transfer between Disparate Mechanical Resonators
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
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
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
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 , where is the cosmological constant, in addition to the
particle-mass source term . The resulting
Schr\"{o}dinger-Newton- (S-N-) 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- 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- 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
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
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