Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1990. / Vita. / Includes bibliographical references (leaves 243-248). / by Terence Tai-Li Hwa. / Ph.D.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2009. / Includes bibliographical references (p. 57). / In this thesis I explore the theoretical model based on Asakawa and Nonaka's idea[l]. I start by arguing that the critical point of the QCD phase diagram is second order and belongs to the three dimensional Ising model universality class. Then the singular part of the equation of state is derived. The singular part and non-singular part equation of state are glued together to find the general form of the equation of state. This equation of state includes the critical point. With this equation of state, we construct the isentropic trajectories. The pathology of these trajectories is discussed. Moreover the validation of the signature of the critical point suggested by Asakawa and Nonaka is also discussed. / by Wathid Assawasunthonnet. / S.B.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 129-134). / This thesis comprises three results on quantum algorithms and quantum process tomography. In the first section, I create a tool that uses properties of the quantum general adversary bound to upper bound the query complexity of Boolean functions. Using this tool I prove the existence of O(1)-query quantum algorithms for a set of functions called FAULT TREES. To obtain these results, I combine previously known properties of the adversary bound in a new way, as well as extend an existing proof of a composition property of the adversary bound. The second result is a method for characterizing errors in a quantum computer. Many current tomography procedures give inaccurate estimates because they do not have adequate methods for handling noise associated with auxiliary operations. The procedure described here provides two ways of dealing with this noise: estimating the noise independently so its effect can be completely understood, and analyzing the worst case effect of this noise, which gives better bounds on standard estimates. The final section describes a quantum analogue of a classical local search algorithm for Classical k-SAT. I show that for a restricted version of Quantum 2-SAT, this quantum algorithm succeeds in polynomial time. While the quantum algorithm ultimately performs similarly to the classical algorithm, quantum effects, like the observer effect, make the analysis more challenging. / by Shelby Kimmel. / Ph. D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 49). / This thesis presents our work on developing and improving the techniques of trapping and cooling an ultra-cold cloud of Lithium-7 atoms and the realization of the Bose- Einstein condensate as a first step to study quantum magnetism in optical lattice. The techniques used in this experiment include Zeeman slowing, magneto-optical trapping (MOT), gray molasses, static magnetic trapping, evaporative cooling, optical dipole trapping (ODT), etc. The apparatus has the capability of creating a Bose-Einstein condensate with almost 106 atoms in 10 seconds as well as tuning the interaction between atoms in a BEC using the Feshbach resonance with a magnetic bias field of up to ~~ 1000G. / by Yichao Yu. / S.B.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 325-374). / Indirect detection is the search for the particle nature of dark matter with astrophysical probes. Manifestly, it exists right at the intersection of particle physics and astrophysics, and the discovery potential for dark matter can be greatly extended using insights from both disciplines. This thesis provides an exploration of this philosophy. On the one hand, I will show how astrophysical observations of dark matter, through its gravitational interaction, can be exploited to determine the most promising locations on the sky to observe a particle dark matter signal. On the other, I demonstrate that refined theoretical calculations of the expected dark matter interactions can be used disentangle signals from astrophysical backgrounds. Both of these approaches will be discussed in the context of general searches, but also applied to the case of an excess of photons observed at the center of the Milky Way. This galactic center excess represents both the challenges and joys of indirect detection. Initially thought to be a signal of annihilating dark matter at the center of our own galaxy, it now appears more likely to be associated with a population of millisecond pulsars. Yet these pulsars were completely unanticipated, and highlight that indirect detection can lead to many new insights about the universe, hopefully one day including the particle nature of dark matter. / by Nicholas Llewellyn Rodd. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1955. / Vita. / Includes bibliographical references (leaf 117). / by Jy Dutton Conant Little. / Ph.D.

Massachusetts Institute of Technology. Dept. of Physics. Thesis. 1971. Ph.D. / Vita. / Includes bibliographical references. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1995. / Includes bibliographical references (p. 107-109). / by Joseph Anthony Giaime. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 159-163). / In this thesis the jet fragmentation function of inclusive jets with transverse momentum PT > 100 GeV/c in PbPb collisions is measured for reconstructed charged particles with PT > 1 GeV/c within the jet cone. A data sample of PbPb collisions collected in 2011 at a center-of-mass energy of [square root of]sNN = 2.76 TeV corresponding to an integrated luminosity of 150 [mu]b-1 is used. The results for PbPb collisions as a function of collision centrality are compared to reference distributions based on pp data collected at the same collision energy. A centrality-dependent modification of the fragmentation function is revealed. For the most central collisions a significant enhancement is observed in the PbPb/pp fragmentation function ratio for the charged particles with PT less than 3 GeV/c. / by Frank Teng Ma. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 105-106). / In this thesis, I developed code in the MEEP finite-difference time domain classical electromagnetic solver to simulate the quantum phenomenon of spontaneous emission and its enhancement by a photonic crystal. The results of these simulations were favorably cross-checked with semi-analytical predictions and experimental results. This code was further extended to simulate spontaneous emission from the top half of a sphere, where the top half is a dielectric material and the bottom half is a metal, in order to determine how effective the metal is at reflecting the emission toward the top. Separately, I used the SCUFF-EM boundary element method classical electromagnetic solver to simulate absorption and scattering, together called extinction, of infrared light from nanoparticles, and used those results to optimize the nanoparticle shapes and sizes for extinction at the desired infrared wavelength. / by Prashanth Sanjeev Venkataram. / S.B.