Covariant calculation of general relativistic effects in an orbiting gyroscope experiment clifford m. In this work we address such a regime and present a scheme which opens a feasible experimental route in this. Atom interferometry we look into new physical tools for initializing, reading out, and increasing the interrogation times of atom interferometers. In special relativity, an object that has a mass cannot travel at the speed of light. Covariant calculation of general relativistic effects in an. For a detailed discussion of how to calculate phase shifts in atom interferometry, see 9. Testing general relativity with atom interferometry savas dimopoulos, peter w. Sr atom interferometry with the optical clock transition as a gravimeter and a gravity. Theoretical approach to highprecision atom interferometry. Pdf an atom interferometer testing the universality of free fall and. Current attempts to probe general relativistic effects in quantum mechanics focus on precision measurements of phase shifts in matterwave interferometry.
Aug 19, 20 however, one of the main limitations in atomic interferometry has been discriminating the different contributions to the interference signal. Atomfield interaction at intersection of laser and atom geodesics. Muller h, chiow sw, herrmann s and chu s 2008 atom interferometry tests of the isotropy of postnewtonian gravity phys. We show how our expressions can be used to calculate and discuss phase shifts in the context of matterwave interferometry especially atom or antiatom interferometry. Since atom interferometers were first realized about 20 years ago, atom interferometry. Atom interferometry for detection of gravitational waves. Now, mark kasevich from stanford university, california, and colleagues have used an atom interferometer to measure the effect of the tidal forcewhich is closely related to the curvature of spacetime and thereby to the fundamental description of gravity in general relativity on an individual particles matter wave, or wave function. We begin by explaining the non relativistic calculation of the phase shift in an atom. General relativistic effects in atom interferometry. Phase shift in an atom interferometer due to spacetime curvature across its wave function peter asenbaum,1 chris overstreet,1 tim kovachy,1 daniel d. These lectures were given in the varenna summer school on atom interferometry. A beam of light is split and the two beams are made to follow the same path but in opposite directions.
Tests of fundamental physics using atom interferometry. Atom field interaction at intersection of laser and atom geodesics. Same relativistic effects on superposition components e. Testing general relativity with atom interferometry peter graham stanford savas dimopoulos jason hogan mark kasevich with prd 78 2008 arxiv.
This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests. Theoretical tools for atom optics and interferometry. In addition, general relativity is the basis of current cosmological models of a consistently expanding universe. Many researchers also use atom interferometry as a means of researching fundamental questions in. Actually, this is just the vanguard of a new field exploring experimentally the interface between quantum mechanics and gravity. A general introduction to atom interferometry is provided here as background. Suppresses time varying effects mirror motion, laser phase, etc. A prominent example of such an explanation is the color of gold. Kasevich1 1department of physics, stanford university, stanford, california 94305, usa 2school of physics and astronomy, university of birmingham, birmingham b15 2tt, united kingdom. As the object approaches the speed of light, the objects energy and momentum increase without bound. February 6, 2008 the unprecedented precision of atom interferometry will soon lead to laboratory tests of general. In the theory of general relativity, time is not a global background parameter but flows at different rates depending on the spacetime geometry. General relativistic effects in quantum interference of photons.
By doug marett 2012 a number of authors have suggested that the sagnac effect contradicts the original postulates of special relativity, since the postulate of the constancy of the speed of light is violated in rotating systems. In contrast to this intuition, we show that i closed lightpulse interferometers without clock transitions during the pulse sequence. It will also probe general relativistic effectssuch as the nonlinear threegraviton coupling, the gravity of an atoms kinetic energy, and the. Quantum interferometric visibility as a witness of general. Bragg diffraction is comparable to a hardwall reflection if the bragg condition is exactly fulfilled. Path integral formulation to obtain quantum phases. It will also probe general relativistic effects such as the nonlinear threegraviton coupling, the gravity of an atom s kinetic energy, and the falling of light to several decimals. A pulsed atom laser is outputcoupled from a boseeinstein condensate and propagates through a sequence of two internal state beam splitters, realized via coherent raman transitions between the two. New relativistic gravitational effects using chargedparticle. Although verified to high precision in various experiments1, this prediction as well as any other general relativistic effect has never been tested in the regime where quantum effects become relevant. In addition, the apparatus is sensitive enough to begin measuring novel general relativistic effects that have never been measured in a laboratory environment1.
Although the physical pictures are quite different, the conceptual problems that arise in both cases, the neutron and atom interferometers, are quite similar, and yet the relativistic effects show up quite differently. Relativistic quantum chemistry combines relativistic mechanics with quantum chemistry to explain elemental properties and structure, especially for the heavier elements of the periodic table. The other work concerns molecular calculations, where relativistic effects on bonding, bondlengths and spectroscopy of molecules containing heavy elements are studied. Similar to optical interferometers, atom interferometers measure the difference in phase between atomic matter waves along different paths. For a treatment of atom interferometry relevant to the detection of gravitational waves specifically, see 2. General relativity effects on equation of motion d. We present results on a freespace atom interferometer operating on the first order magnetically insensitive f1,mf0. Therefore this thesis starts with a chapter on atomic relativistic effects, after a general introduction about relativity and the method of calculation in chapter 1. Yet, phase shifts can always be explained as arising because of an aharonovbohm effect, where a particle in a flat spacetime is subject to an effective potential. Generated by moving mass instead of electric charge tests of gravity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity.
Phase shift in an atom interferometer due to spacetime. The potentially testable relativistic effects include the nonlinear threegraviton coupling, the. We report the demonstration of a sagnac effect atom interferometer gyroscope which. Only if the particle is at rest relative to an observer so that p 0 does e, which is now called the rest energy and usually denoted by e 0, equal m c 2. Hogan j m and kasevich m a 2008 general relativistic effects in atom interferometry phys. Relativistic mass an overview sciencedirect topics. Many researchers also use atom interferometry as a means of researching fundamental questions in quantum mechanics. Pdf comment on relativistic effects in atom and neutron. Tim kovachy, new techniques for precision atom interferometry and applications to fundamental tests of gravity and of quantum mechanics, stanford 2016 81 mb susannah dickerson, longtime atom interferometry for precision tests of fundamental physics, stanford 2014 18 mb alex sugarbaker, atom interferometry in a 10 m fountain, stanford, 2014. However, in a neutron interferometer in the gravitational field cow experiment this is not the case and the momentum transfers should not be. Interactions between atoms and electromagnetic cavities. Some predictions of einsteins general relativity involve the socalled framedragging effects, which can be viewed as manifestations of machs principle, a term coined by einstein in reference to the statement, or conjecture, that all. General relativistic effects in atom interferometry core. The field of atom interferometry has expanded rapidly in recent years, and todays research laboratories are using atom interferometers both as inertial sensors and for precision measurements.
We show that the language of atom interferometry 1 provides a unified picture. Do general relativistic effects limit experiments to test the universality of free fall and the weak equivalence principle. We are about to enter a new era for atom interferometry where the rapid advance of these techniques will hopefully allow many new tests of fundamental physics gravity waves general relativity and the equivalence principle short distance gravity quantum mechanics e. Navigation oil exploration interactions of atoms with surfaces. Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity.
Testing general relativity with atom interferometry savas dimopoulos with peter graham jason hogan mark kasevich. General relativistic effects in quantum interference of. Testing general relativity with atom interferometry savas dimopoulos. Predicted by general relativity, these gravitational waves should be triggered by the movement of astronomical bodies, such as merging black holes, but have yet to be detected directly. Some gravitational effects of interest for atomic interferometry are derived, including spingravitation effects. Oct 18, 2011 current attempts to probe general relativistic effects in quantum mechanics focus on precision measurements of phase shifts in matterwave interferometry.
As a consequence, these phenomena can be interpreted as an effect of an underlying geometry. They discuss a general relativistic formulation of atom interferometry and the use of this formulation to understand gravitational wave detection with atom interferometry. Atom interferometry for detection of gravitational waves niac 20 spring symposium chicago jason hogan stanford university march 12, 20. The colella overhauserwerner cow type of neutron interferometer and the kasevichchu kc atom interferometer, are the prototype of such devices and the issue of whether they are sensitive to relativistic effects has recently aroused much controversy. To see the effect of a gravitational wave on the differential phase between the. Apr 26, 20 a read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Taking atom interferometric quantum sensors from the. New frontiers at the interface of general relativity and quantum optics 125 on a lighter note it is amusing but not too surprising that in a paper dedicated to the discussion of rotation a great variety of spirals make their appearance in unexpected places. From this we develop a method for calculating the phase shift in general relativity.
We will consider using atom interferometry to test gravity. Our experiment relies on the coherent manipulation of atomic quantum states using light pulses19,20. Atom interferometry detection of gravitational waves. Some of the advanced atom interferometer techniques that we are developing can also be applied to next generation inertial sensors, potentially improving. Pdf lightpulse atom interferometers constitute powerful quantum sensors for inertial forces. Published 18 october 2012 2012 iop publishing ltd classical and quantum gravity, volume 29, number 22. Brightdark fringes at the output of an atom interferometer result from phase shifts induced by multiple inertial effects as well as interferometer imperfections. Oct 28, 2019 since the first proofofprinciple experiments over 25 years ago, atom interferometry has matured to a versatile tool that can be used in fundamental research in particle physics, general. The use of becs in atom interferometers should allow for more sophisticated tests of general relativity. Sr atom interferometry with the optical clock transition. Likewise, it is important to probe quantum phenomena in regimes where general relativistic effects are present, for example, where time is not a common parameter for different amplitudes of a single quantum system in superposition.
Relativistic effects in atom and neutron interferometry and. The potentially testable relativistic effects include the nonlinear threegraviton coupling, the gravity of kinetic energy, and the falling of light. October 11, 2006 the unprecedented precision of atom interferometry will soon lead to laboratory tests of general. Atom interferometry for detection of gravitational waves niac 20 spring symposium chicago jason hogan. Atom interferometry for detection of gravitational waves nasa. An atom interferometer is an interferometer which uses the wave character of atoms.
In contrast with astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables. This theory is used to calculate and discuss relativistic phase shifts in the context of matterwave interferometry especially atom or antiatom interferometry. These notes were compiled from our previous papers on these subjects, which contain more detail. In several appendices, the link with the canonical approach in general relativity is established and a generalized stationary phase method is used to calculate the outgoing spinor. Jun 16, 2016 i am trying to answer the first part without going to the relativistic effect. The sagnac effect manifests itself in a setup called a ring interferometer. New frontiers at the interface of general relativity and quantum optics. For example, atom interferometry can be described most conveniently with the help of. Atomic clocks and atom interferometry springerlink. Relativistic effects in atom and neutron interferometry.
A precision measurement of the gravitational redshift by. Hence, it is conceivable that atom interferometers measure general relativistic timedilation effects. This technique is particularly valuable for investigating interferometry schemes sensitive to relativistic effects. General relativistic framework for atomic interferometry. Precision atom interferometry for fundamental physics. Introduction to atom interferometry university of arizona. We report the demonstration of a sagnac effect atom interferometer gyroscope which uses stimulated raman transitions to coherently. We use telecombased laser sources that provide highfrequency stability and power in a compact and integrated setup21.
Testing the equivalence principle by dropping atoms. Potential applications of atom interferometry atom gyroscope sagnac effect geophysics variations in rate of earths rotation general relativity effects. Proposal for a satellite test of the coriolis prediction of general relativity, department of defense. In recent years there has been an enormous progress in matter wave interferometry. But you dont necessarily need a spaceship zooming at near the speed of light to see relativistic effects. These include phase shifts due to the gravitationally induced schiffbarnhill field, rotationally induced london moment, and the modification of the aharonovbohm type of phase shifts, due to the general relativistic.
Future applications range from tests of general relativity to the development of. Pdf we compare a conventional machzehnder lightpulse atom interferometer based on diffractive mirrors with one that uses. The sagnac effect, also called sagnac interference, named after french physicist georges sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. Testing the equivalence principle with atomic interferometry. Kasevich is also studying how atom interferometry could be used to detect ripples in spacetime. A possible application to gravitational wave detection is outlined. We give covariant equations for a twolevel spin 12 atom interacting with laser fields in a gravitational background.
Magdalena zych 1, fabio costa 1, igor pikovski 1, timothy c ralph 2 and caslav brukner 1,3. Therefore, when it absorbs particular quanta of energy, it jumps to the higher level which corresponds to the new energy amount in. The phase of matter waves depends on proper time and is therefore susceptible to special relativistic kinematic and gravitational redshift time dilation. The rotation of the earth has already proven to be an important factor in earlier precision experiments, but it could be overcome in a genuine space experiment, that is, if we neglect subtle effects such as general relativistic frame dragging, which are another motivation for atom interferometry in space. General relativity also predicts the existence of gravitational waves, which have since been observed directly by the physics collaboration ligo. We also discuss future applications of this technology, such as remote sensing of geophysical effects, gravitational wave detection, and. To this end, we establish a relation between special relativistic time dilation and kinematic asymmetry of closed atom interferometers, taking the form of recoil measurements.
Testing general relativity with atom interferometry. New frontiers at the interface of general relativity and. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational. Enhanced atom interferometer readout through the application. A satellite mission in fundamental physics based on high. Relativistic phase shifts for dirac particles interacting.
We begin by explaining the non relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. General relativistic effects in atom interferometry slac stanford. A new class of gravitational effects, in the quantum interference of charged particles, are studied in electron interferometry and superconducting josephson interferometry. Kasevich department of physics, stanford university, stanford, california 94305 dated. Taking atom interferometric quantum sensors from the laboratory to. Principle of equivalence only tidal effects measurable. Detecting inertial effects with airborne matterwave. Relativistic corrections for energy and mass need to be made because of the fact that the speed of light in a vacuum is constant in all reference frames.
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