11 results on '"Deshpande, Tejas"'
Search Results
2. Coriolis force compensation and laser beam delivery for 100-m baseline atom interferometry.
- Author
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Glick, Jonah, Chen, Zilin, Deshpande, Tejas, Wang, Yiping, and Kovachy, Tim
- Subjects
CORIOLIS force ,LASER beams ,FIBER lasers ,LASER interferometry ,LASER pulses ,ATOMIC beams ,INTERFEROMETRY - Abstract
The Coriolis force is a significant source of systematic phase errors and dephasing in atom interferometry and is often compensated by counter-rotating the interferometry laser beam against Earth's rotation. We present a novel method for performing Coriolis force compensation for long-baseline atom interferometry, which mitigates atom-beam misalignment due to beam rotation, an effect which is magnified by the long lever arm of the baseline length. The method involves adjustment of the angle of the interferometer beam prior to a magnifying telescope, enabling the beam to pivot around a tunable position along the interferometer baseline. By tuning the initial atom kinematics and adjusting the angle with which the interferometer beam pivots about this point, we can ensure that the atoms align with the center of the beam during the atom optics laser pulses. This approach will be used in the MAGIS-100 atom interferometer and could also be applied to other long-baseline atom interferometers. An additional challenge associated with long baseline interferometry is that since long-baseline atom interferometers are often located outside of typical laboratory environments, facilities constraints may require lasers to be housed in a climate-controlled room a significant distance away from the main experiment. Nonlinear effects in optical fibers restrict the use of fiber-based transport of the high-power interferometry beam from the laser room to the experiment. We present the design of and prototype data from a laser transport system for MAGIS-100 that maintains robustness against alignment drifts despite the absence of a long fiber. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. High-power, low-phase-noise, frequency-agile laser system for delivering fiber-noise-cancelled pulses for Strontium clock atom interferometry
- Author
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DeRose, Kenneth, Deshpande, Tejas, Wang, Yiping, and Kovachy, Tim
- Subjects
Atomic Physics (physics.atom-ph) ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,General Relativity and Quantum Cosmology ,Optics (physics.optics) ,Physics - Optics ,Physics - Atomic Physics - Abstract
We present the development of a laser system for performing single-photon atom interferometry on the 698 nm clock transition in ultracold Strontium. We coherently combine the power of two Titanium:Sapphire lasers and demonstrate chirps of 200 MHz in 2.5 ms while phase-locked to an optical reference. Moreover, we demonstrate a novel scheme to deliver 4 W pulsed beams to the atoms via a mode-cleaning optical fiber using active noise cancellation., 5 pages, 3 figures
- Published
- 2022
4. The prevalence and risk factors of depression in engineering college students: A cross-sectional study.
- Author
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Debnath, Dhrubajyoti, Deshpande, Tejas, Gupta, Digant, Yadav, Arun, Pandve, Harshal, Marimuthu, Yamini, and Deshmukh, Pradeep
- Subjects
DEPRESSION in college students ,INTERPERSONAL conflict ,CROSS-sectional method ,LOGISTIC regression analysis ,PSYCHOLOGICAL stress - Abstract
Background: Engineering students like any other students face several stressors in their lives, which make them vulnerable to depression. Depression may affect students' academic performance. Aim: The present study aims to estimate the prevalence and associated risk factors of depression among engineering students. Material and Methods: A cross-sectional study was conducted in December 2016 among 110 randomly selected students from an engineering college in a rural area of Pune district, India. PHQ-9 questionnaire was used. Univariate and multivariable ordinal logistic regression was used to quantify association. Results: Of a total of 110 students, 71.8% were males, while 28.2% were females. The mean age was 20.7 years. 29.1% had no depression, 48.2% had mild depression, and 22.7% had moderate depression. Univariate analysis found four variables significantly associated with a greater risk of depression: parental stress, sibling stress, economic stress, and interpersonal conflict. In the adjusted (multivariable) ordinal logistic regression analysis controlling for all independent variables, only lack of economic support and interpersonal conflicts retained their statistical significance. Conclusion: The prevalence of depression in engineering students is high and strongly associated with the presence of economic and personal stress. Screening for depression and giving them care and support is of paramount importance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Enhancing strontium clock atom interferometry using quantum optimal control
- Author
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Chen, Zilin, Louie, Garrett, Wang, Yiping, Deshpande, Tejas, and Kovachy, Tim
- Subjects
Quantum Physics ,FOS: Physical sciences ,Quantum Physics (quant-ph) - Abstract
Strontium clock atom interferometry is a promising new technique, with multiple experiments under development to explore its potential for dark matter and gravitational wave detection. In these detectors, large momentum transfer (LMT) using sequences of many laser pulses is necessary, and thus high fidelity of each pulse is important since small infidelities become magnified. Quantum Optimal Control (QOC) is a framework for developing control pulse waveforms that achieve high fidelity and are robust against experimental imperfections. Resonant single-photon transitions using the narrow clock transition of strontium involve significantly different quantum dynamics than more established atom interferometry methods based on far-detuned two-photon Raman or Bragg transitions, which leads to new opportunities and challenges when applying QOC. Here, we study QOC pulses for strontium clock interferometry and demonstrate their advantage over basic square pulses (primitive pulses) and composite pulses in terms of robustness against multiple noise channels. This could improve the scale of large momentum transfer in Sr clock interferometers, paving the way to achieve these scientific goals., 7 pages, 5 figures
- Published
- 2022
6. Development of Tools for Probing Order in Single Crystals Using Electron and Photon Spectroscopy
- Author
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Deshpande, Tejas Makarand
- Subjects
Ultrahigh vacuum ,Cryogenics ,Lasers ,Topological superconductors ,Angle-Resolved Photoelectron Spectroscopy ,Condensed matter physics ,Applied Physics - Abstract
Discovering novel quantum phases of matter–from emergent behavior of strongly-correlated electrons in solid-state systems to superfluidity in quantum degenerate liquids–has been a cornerstone of condensed matter physics for many decades. In the most recent decades, however, the discovery of topological phases has emphasized the importance of symmetry, in addition to the conventional paradigm of symmetry breaking, in the definition of the order parameter, Ψ, and hence the quantum phase it represents. Naturally, novel experimental tools, capable of coupling to said order parameter, directly or indirectly, are required to discover conventionally elusive quantum phases. In this thesis, I will discuss experimental techniques, using both photon and electron spectroscopy, to study exotic electronic phases in single crystals. The thesis will be divided into two unequal parts: (a) the development of a high-energy-resolution sub-Kelvin angle-resolved photoemission spectroscopy apparatus to study 3D time-reversal invariant topological superconductors, and (b) the experiments exploiting the non-linear and time-resolved aspects of femtosecond lasers to study a broad class of many-body systems.
- Published
- 2020
- Full Text
- View/download PDF
7. Improving Predictions Using Qualitative Parameters
- Author
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PRASHANT MAHAJAN , PRATIK DESHPANDE , TEJAS NANAWARE, PROF. MAHENDRA PATIL
- Subjects
Machine Learning ,Prediction Models ,Neural Networks ,Behavioral Patterns ,Qualitative Analysis - Abstract
Selecting appropriate parameters while making any prediction model is a tedious task. Often, while constructing a prediction model, categorical variables are ignored. If we include more qualitative parameters for prediction, the observed results will have more accuracy. Neural networks help in a proper learning methodology which utilizes the concept of machine learning. When prediction is to be made, the human behavioral patterns hamper the test results as it plays a crucial role in any decision making. Employing qualitative parameters in decision making, accurate conjectures are possible.
- Published
- 2018
- Full Text
- View/download PDF
8. Proposed Battlefield Simulator Using GPU.
- Author
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Chaware, S. M., Udawant, Omkar, Joshi, Kiran, and Deshpande, Tejas
- Published
- 2018
- Full Text
- View/download PDF
9. Inversion symmetry and bulk Rashba effect in methylammonium lead iodide perovskite single crystals.
- Author
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Frohna, Kyle, Deshpande, Tejas, Harter, John, Wei Peng, Barker, Bradford A., Neaton, Jeffrey B., Louie, Steven G., Bakr, Osman M., Hsieh, David, and Bernardi, Marco
- Subjects
RASHBA effect ,LEAD iodide ,SINGLE crystals ,CHARGE carrier lifetime ,SECOND harmonic generation ,PEROVSKITE - Abstract
Methylammonium lead iodide perovskite (MAPbI
3 ) exhibits long charge carrier lifetimes that are linked to its high efficiency in solar cells. Yet, the mechanisms governing these unusual carrier dynamics are not completely understood. A leading hypothesis-disproved in this work-is that a large, static bulk Rashba effect slows down carrier recombination. Here, using second harmonic generation rotational anisotropy measurements on MAPbI3 crystals, we demonstrate that the bulk structure of tetragonal MAPbI3 is centrosymmetric with I4/mcm space group. Our calculations show that a significant Rashba splitting in the bandstructure requires a non-centrosymmetric lead iodide framework, and that incorrect structural relaxations are responsible for the previously predicted large Rashba effect. The small Rashba splitting allows us to compute effective masses in excellent agreement with experiment. Our findings rule out the presence of a large static Rashba effect in bulk MAPbI3 , and our measurements find no evidence of dynamic Rashba effects. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
10. Effective Educational Methods for Teaching Assistants in a First-Year Engineering MATLAB® Course.
- Author
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heeg, joshua jude, Flenar, Kyle, Ross, Jordan Alexander, Okel, Taylor, Deshpande, Tejas Abhijit, Bucks, Gregory Warren, and Ossman, Kathleen A.
- Subjects
ENGINEERING education in universities & colleges ,MATHEMATICS education (Higher) ,INTERDISCIPLINARY education ,TEACHERS' assistants ,ENGINEERING -- Examinations, questions, etc. ,CURRICULUM - Abstract
At the University of Cincinnati, two courses were introduced during the 2012-2013 school year to provide first-year students with hands-on experience in engineering and form a link between engineering and the required mathematics and science courses. These interdisciplinary courses form a two-semester sequence in which students apply fundamental theory from algebra, trigonometry, calculus and physics to relevant engineering applications. MATLAB is introduced as a programming tool to enable students to explore engineering concepts, investigate solutions to complex problems, analyze and present data effectively, and to develop an appreciation for the power and limitations of computing tools. In an effort to improve the learning of students in the course, three sets of two teaching assistants each (TAs) tested a different educational method in the lab portion of the courses. These methods were identified by the TAs after teaching students for several weeks and analyzing the common pitfalls encountered by the students. In the first method, the TAs focus on complimenting students on their performance and encouraging them to break up the problem into smaller, more manageable steps. This fosters an engineering mindset that hopes to assist the students intimidated by programming or those that struggle with starting the problem. The next method tested involved the TAs asking questions about the coding concepts the students were using to encourage a deeper level of thought and understanding with the assignment. Lastly, the TAs questioned the students on the commands used in the lab activity and provided some initial guidance in starting the code for the assignment. The effectiveness of the different methods was assessed in two ways. In the first, qualitative data, in the form of observations and informal interviews, were collected by the TAs as they implemented the different methodologies. In the second, quantitative data, in the form of student grades on exams and lab assignments are compared between the experimental groups and a control group. The quantitative data was analyzed to support the results of the qualitative analyses. [ABSTRACT FROM AUTHOR]
- Published
- 2014
11. High-power, low-phase-noise, frequency-agile laser system for delivering fiber-noise-canceled pulses for strontium clock atom interferometry.
- Author
-
DeRose K, Deshpande T, Wang Y, and Kovachy T
- Abstract
We present a laser system for performing single-photon atom interferometry on the 698 nm clock transition in ultracold strontium. We coherently combine the power of two titanium:sapphire lasers and demonstrate chirps of 200 MHz in 2.5 ms while phase-locked to an optical reference. Moreover, we demonstrate a novel, to the best of our knowledge, scheme to deliver 4 W pulsed beams to the atoms via a mode-cleaning optical fiber using active noise cancellation.
- Published
- 2023
- Full Text
- View/download PDF
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