georgios vasilakis - Academia.edu (original) (raw)

Papers by georgios vasilakis

CPT and Lorentz Symmetry, 2008

A K-3 He co-magnetometer has been developed for a test of Lorentz and CPT symmetry. Polarized K v... more A K-3 He co-magnetometer has been developed for a test of Lorentz and CPT symmetry. Polarized K vapor forms a spin-exchange relaxation-free (SERF) magnetometer that has record sensitivity of about 1 fT/ √ Hz. The polarized 3 He effectively suppresses sensitivity to the magnetic fields and gradients. Together, the K-3 He comagnetometer retains sensitivity to anomalous, CPT-and Lorentz-violating fields that couple to electron and nuclear spins differently than a normal magnetic field. Data over the course of 15 months provide upper limits on the coupling energy of a CPT-violating field to neutron spin,b n < 1.4 × 10 −31 GeV, to proton spin, b p < 4.4 × 10 −30 GeV, and to electron spin,b e < 1.0 × 10 −28 GeV. These limits are consistent with the existing limits ofb n < 1.1 × 10 −31 GeV (Bear et al., 2002) and b e < 3.0 × 10 −29 GeV (Heckel et al., 2000). The proton sensitivity is better than the published limit ofb p < 1.8 × 10 −27 GeV (Phillips et al., 2001). The long-term sensitivity of the co-magnetometer was significantly limited by sources of systematic noise. The co-magnetometer provides a robust platform for precision measurements primarily due to its inherent insensitivity to magnetic field drift and field gradients. Detailed analytic and numerical modeling of the coupled spin ensemble dynamics provides good agreement with steady state and transient response measurements. iii Elaborate procedures have been developed for running the system optimally and minimizing the magnetic fields and lightshifts in the system. The co-magnetometer also forms a sensitive gyroscope that inherits all the magnetic insensitivity features of the co-magnetometer and adds insensitivity to magnetic field fast transients. The sensitivity of this gyroscope is competitive with existing compact gyroscope techniques. iv Dedicated to Jill Foley First I'd like to thank my advisor Michael Romalis for providing me with this wonderful opportunity. Mike's enthusiasm for this work is infectious and his commitment to finding the answers to these fundamental questions is inspiring. I am also grateful for his hands-on style, nearly constant availability, and patience with my development. I would not have been able to finish this dissertation in such a short amount of time without his prompt reading. I also appreciate the efforts of my careful readers Ernie Valeo and Will Happer, who suggested important improvements. I'd like to thank my dissertation committee: Will Happer, Stewart Zweben, who tirelessly answered my questions in his diagnostics classes, and John Krommes, who taught an excellent and challenging class on irreversible processes. There are many people who have directly helped me in this work: Ioannis Kominis was a joy to work with on the initial magnetometer sensitivity measurements. Igor Savukov has always been available and eager to discuss the finer points of atomic theory and greatly helped with the first major renovation of the experiment. Rajat Ghosh built most of the additions for the gyroscope measurements, which worked very well on the first try. Saee Paliwal built a very useful wavelength feedback box. Tom Jackson wrote what turned out to be an absolutely essential viewing program for the data. vi Mike Souza patiently made and re-made the spherical glass cells that were of critical importance to the experiment. Charles Sule fabricated absolutely bombproof, space-ready electronics. Dan Hoffman was a constant companion and was always was free to help when help was most needed, especially with last-minute machining. I am indebted to Mike Peloso for maintaining a most awesome, accessible and efficient student machine shop. I also deeply appreciate all the pieces made by Bill Dix, Laszlo Varga, Glenn Atkinson, Ted Lewis and everyone else in the machine shop. Mary DeLorenzo, Ellen Webster, Claude Champagne and Kathy Warren provided fantastic and friendly administrative and purchasing support. This work would not have been possible without the support from NASA, NSF, a NIST Precision Measurement grant, and The Packard Foundation. I could not have asked for a better officemate than Micah Ledbetter, who was both a good friend and colleague. The same is true for Scott Seltzer, who has been very supportive and helpful while I have been writing. I benefited tremendously from the faithful companionship of Luis Delgado-Aparicio during our long studies for the plasma physics general exams. I also deeply appreciate the support of the prelims study group: Juan Burwell, Jack Laiho, Wei-Li Lee and Ben North. Everyone in plasma physics has been extremely supportive. I am grateful for the continuous support from Nat Fisch and the program in plasma physics. Phil Efthimion offered tireless encouragement and guidance while I was finishing. Sam Cohen was an inspiring, excellent teacher and oversaw a wonderful first-year project. Barbara Sarfaty has been very supportive and helpful throughout my time here and clearly worked hard to make sure that I never had to worry about administrative details. vii My love of physics was developed with the physics faculty at Swarthmore College: John Boccio, Tom Donnelly, Peter Collings, Frank Moscatelli, Amy Bug and others held me to very high standards. In particular, working with Michael Brown on spheromak plasmas was an incredible experience that cemented my trajectory into graduate school. My interests in physics started with John Peterson in 7th grade science class and continued with excellent teaching by Kathy Sweeney-Hammond, David Walker and Jennifer Groppe. Jennifer, in particular, ran the Engineering Team, which I loved, and the skills that I learned would become useful later in building physics experiments. My general interest in academia became much deeper during an amazing history class by Leonard King. I'd like to thank my parents Mom and Dad for being so loving and supportive of my interests throughout the years. They tirelessly encouraged me, enabled me and gave me the confidence to pursue my dreams. Though I met Jill Foley as a fellow student and lab mate, she has become so much more to me and I am filled with joy that we will wed shortly hereafter. For her trusted advice on all things, both in physics and on other aspects of life, for providing healthy, tasty sustenance, and especially for her limitless, loving support throughout this work, I dedicate this thesis to her.

Polarized atomic vapors can be used to detect fields interacting with a spin. Recent advances hav... more Polarized atomic vapors can be used to detect fields interacting with a spin. Recent advances have extended the sensitivity of atomic magnetometers to a level favorable for fundamental physics research, and in many cases the sensitivity approaches quantum metrology limits. In this thesis, we present a high density atomic K-3 He comagnetometer, which features suppressed sensitivity to magnetic fields, but retains sensitivity to anomalous fields that couple differently than a magnetic field to electron and nuclear spins. The comagnetometer was used to measure interactions with a separate optically pumped

CPT and Lorentz Symmetry, 2008

A K-3 He co-magnetometer has been developed for a test of Lorentz and CPT symmetry. Polarized K v... more A K-3 He co-magnetometer has been developed for a test of Lorentz and CPT symmetry. Polarized K vapor forms a spin-exchange relaxation-free (SERF) magnetometer that has record sensitivity of about 1 fT/ √ Hz. The polarized 3 He effectively suppresses sensitivity to the magnetic fields and gradients. Together, the K-3 He comagnetometer retains sensitivity to anomalous, CPT-and Lorentz-violating fields that couple to electron and nuclear spins differently than a normal magnetic field. Data over the course of 15 months provide upper limits on the coupling energy of a CPT-violating field to neutron spin,b n < 1.4 × 10 −31 GeV, to proton spin, b p < 4.4 × 10 −30 GeV, and to electron spin,b e < 1.0 × 10 −28 GeV. These limits are consistent with the existing limits ofb n < 1.1 × 10 −31 GeV (Bear et al., 2002) and b e < 3.0 × 10 −29 GeV (Heckel et al., 2000). The proton sensitivity is better than the published limit ofb p < 1.8 × 10 −27 GeV (Phillips et al., 2001). The long-term sensitivity of the co-magnetometer was significantly limited by sources of systematic noise. The co-magnetometer provides a robust platform for precision measurements primarily due to its inherent insensitivity to magnetic field drift and field gradients. Detailed analytic and numerical modeling of the coupled spin ensemble dynamics provides good agreement with steady state and transient response measurements. iii Elaborate procedures have been developed for running the system optimally and minimizing the magnetic fields and lightshifts in the system. The co-magnetometer also forms a sensitive gyroscope that inherits all the magnetic insensitivity features of the co-magnetometer and adds insensitivity to magnetic field fast transients. The sensitivity of this gyroscope is competitive with existing compact gyroscope techniques. iv Dedicated to Jill Foley First I'd like to thank my advisor Michael Romalis for providing me with this wonderful opportunity. Mike's enthusiasm for this work is infectious and his commitment to finding the answers to these fundamental questions is inspiring. I am also grateful for his hands-on style, nearly constant availability, and patience with my development. I would not have been able to finish this dissertation in such a short amount of time without his prompt reading. I also appreciate the efforts of my careful readers Ernie Valeo and Will Happer, who suggested important improvements. I'd like to thank my dissertation committee: Will Happer, Stewart Zweben, who tirelessly answered my questions in his diagnostics classes, and John Krommes, who taught an excellent and challenging class on irreversible processes. There are many people who have directly helped me in this work: Ioannis Kominis was a joy to work with on the initial magnetometer sensitivity measurements. Igor Savukov has always been available and eager to discuss the finer points of atomic theory and greatly helped with the first major renovation of the experiment. Rajat Ghosh built most of the additions for the gyroscope measurements, which worked very well on the first try. Saee Paliwal built a very useful wavelength feedback box. Tom Jackson wrote what turned out to be an absolutely essential viewing program for the data. vi Mike Souza patiently made and re-made the spherical glass cells that were of critical importance to the experiment. Charles Sule fabricated absolutely bombproof, space-ready electronics. Dan Hoffman was a constant companion and was always was free to help when help was most needed, especially with last-minute machining. I am indebted to Mike Peloso for maintaining a most awesome, accessible and efficient student machine shop. I also deeply appreciate all the pieces made by Bill Dix, Laszlo Varga, Glenn Atkinson, Ted Lewis and everyone else in the machine shop. Mary DeLorenzo, Ellen Webster, Claude Champagne and Kathy Warren provided fantastic and friendly administrative and purchasing support. This work would not have been possible without the support from NASA, NSF, a NIST Precision Measurement grant, and The Packard Foundation. I could not have asked for a better officemate than Micah Ledbetter, who was both a good friend and colleague. The same is true for Scott Seltzer, who has been very supportive and helpful while I have been writing. I benefited tremendously from the faithful companionship of Luis Delgado-Aparicio during our long studies for the plasma physics general exams. I also deeply appreciate the support of the prelims study group: Juan Burwell, Jack Laiho, Wei-Li Lee and Ben North. Everyone in plasma physics has been extremely supportive. I am grateful for the continuous support from Nat Fisch and the program in plasma physics. Phil Efthimion offered tireless encouragement and guidance while I was finishing. Sam Cohen was an inspiring, excellent teacher and oversaw a wonderful first-year project. Barbara Sarfaty has been very supportive and helpful throughout my time here and clearly worked hard to make sure that I never had to worry about administrative details. vii My love of physics was developed with the physics faculty at Swarthmore College: John Boccio, Tom Donnelly, Peter Collings, Frank Moscatelli, Amy Bug and others held me to very high standards. In particular, working with Michael Brown on spheromak plasmas was an incredible experience that cemented my trajectory into graduate school. My interests in physics started with John Peterson in 7th grade science class and continued with excellent teaching by Kathy Sweeney-Hammond, David Walker and Jennifer Groppe. Jennifer, in particular, ran the Engineering Team, which I loved, and the skills that I learned would become useful later in building physics experiments. My general interest in academia became much deeper during an amazing history class by Leonard King. I'd like to thank my parents Mom and Dad for being so loving and supportive of my interests throughout the years. They tirelessly encouraged me, enabled me and gave me the confidence to pursue my dreams. Though I met Jill Foley as a fellow student and lab mate, she has become so much more to me and I am filled with joy that we will wed shortly hereafter. For her trusted advice on all things, both in physics and on other aspects of life, for providing healthy, tasty sustenance, and especially for her limitless, loving support throughout this work, I dedicate this thesis to her.

Polarized atomic vapors can be used to detect fields interacting with a spin. Recent advances hav... more Polarized atomic vapors can be used to detect fields interacting with a spin. Recent advances have extended the sensitivity of atomic magnetometers to a level favorable for fundamental physics research, and in many cases the sensitivity approaches quantum metrology limits. In this thesis, we present a high density atomic K-3 He comagnetometer, which features suppressed sensitivity to magnetic fields, but retains sensitivity to anomalous fields that couple differently than a magnetic field to electron and nuclear spins. The comagnetometer was used to measure interactions with a separate optically pumped