2024-25 Courses
- Electrodynamics
PHYSICS 121 (Spr) - Electromagnetism
PHYSICS 120 (Win) -
Independent Studies (5)
- Curricular Practical Training
APPPHYS 291 (Aut, Win, Spr, Sum) - Directed Studies in Applied Physics
APPPHYS 290 (Aut, Win, Spr, Sum) - Independent Research and Study
PHYSICS 190 (Aut, Win, Spr, Sum) - Research
PHYSICS 490 (Aut, Win, Spr, Sum) - Senior Thesis Research
PHYSICS 205 (Aut, Win, Spr, Sum)
- Curricular Practical Training
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Prior Year Courses
2023-24 Courses
- Intermediate Electricity and Magnetism I
PHYSICS 120 (Win) - Intermediate Electricity and Magnetism II
PHYSICS 121 (Spr)
2022-23 Courses
- Intermediate Electricity and Magnetism I
PHYSICS 120 (Win) - Intermediate Electricity and Magnetism II
PHYSICS 121 (Spr)
2021-22 Courses
- Intermediate Electricity and Magnetism I
PHYSICS 120 (Win)
- Intermediate Electricity and Magnetism I
Stanford Advisees
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Doctoral Dissertation Reader (AC)
Sanha Cheong, Jason Corbin, Joseph Curti, Minjeong Kim, Kuan-Yu Lin, Michelle Wu -
Postdoctoral Faculty Sponsor
Michael Van de Graaff -
Doctoral Dissertation Advisor (AC)
Mahiro Abe, Rachel Barcklay, Sam Carman, Yijun Jiang, Megan Nantel, Hunter Swan, Dhruv Tandon
All Publications
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Matter-wave Atomic Gradiometer Interferometric Sensor (MAGIS-100)
QUANTUM SCIENCE AND TECHNOLOGY
2021; 6 (4)
View details for DOI 10.1088/2058-9565/abf719
View details for Web of Science ID 000673145000001
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AEDGE: Atomic experiment for dark matter and gravity exploration in space
EXPERIMENTAL ASTRONOMY
2021
View details for DOI 10.1007/s10686-021-09701-3
View details for Web of Science ID 000628085300001
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AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space
EPJ QUANTUM TECHNOLOGY
2020; 7 (1)
View details for DOI 10.1140/epjqt/s40507-020-0080-0
View details for Web of Science ID 000519468200001
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Large Momentum Transfer Clock Atom Interferometry on the 689 nm Intercombination Line of Strontium
PHYSICAL REVIEW LETTERS
2020; 124 (8): 083604
Abstract
We report the first realization of large momentum transfer (LMT) clock atom interferometry. Using single-photon interactions on the strontium ^{1}S_{0}-^{3}P_{1} transition, we demonstrate Mach-Zehnder interferometers with state-of-the-art momentum separation of up to 141 ℏk and gradiometers of up to 81 ℏk. Moreover, we circumvent excited state decay limitations and extend the gradiometer duration to 50 times the excited state lifetime. Because of the broad velocity acceptance of the interferometry pulses, all experiments are performed with laser-cooled atoms at a temperature of 3 μK. This work has applications in high-precision inertial sensing and paves the way for LMT-enhanced clock atom interferometry on even narrower transitions, a key ingredient in proposals for gravitational wave detection and dark matter searches.
View details for DOI 10.1103/PhysRevLett.124.083604
View details for Web of Science ID 000517295000002
View details for PubMedID 32167328
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SAGE: A proposal for a space atomic gravity explorer
EUROPEAN PHYSICAL JOURNAL D
2019; 73 (11)
View details for DOI 10.1140/epjd/e2019-100324-6
View details for Web of Science ID 000496943000001
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Effective Inertial Frame in an Atom Interferometric Test of the Equivalence Principle
PHYSICAL REVIEW LETTERS
2018; 120 (18): 183604
Abstract
In an ideal test of the equivalence principle, the test masses fall in a common inertial frame. A real experiment is affected by gravity gradients, which introduce systematic errors by coupling to initial kinematic differences between the test masses. Here we demonstrate a method that reduces the sensitivity of a dual-species atom interferometer to initial kinematics by using a frequency shift of the mirror pulse to create an effective inertial frame for both atomic species. Using this method, we suppress the gravity-gradient-induced dependence of the differential phase on initial kinematic differences by 2 orders of magnitude and precisely measure these differences. We realize a relative precision of Δg/g≈6×10^{-11} per shot, which improves on the best previous result for a dual-species atom interferometer by more than 3 orders of magnitude. By reducing gravity gradient systematic errors to one part in 10^{13}, these results pave the way for an atomic test of the equivalence principle at an accuracy comparable with state-of-the-art classical tests.
View details for PubMedID 29775337
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Search for light scalar dark matter with atomic gravitational wave detectors
PHYSICAL REVIEW D
2018; 97 (7)
View details for DOI 10.1103/PhysRevD.97.075020
View details for Web of Science ID 000430060800011
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Phase Shift in an Atom Interferometer due to Spacetime Curvature across its Wave Function
PHYSICAL REVIEW LETTERS
2017; 118 (18)
Abstract
Spacetime curvature induces tidal forces on the wave function of a single quantum system. Using a dual light-pulse atom interferometer, we measure a phase shift associated with such tidal forces. The macroscopic spatial superposition state in each interferometer (extending over 16 cm) acts as a nonlocal probe of the spacetime manifold. Additionally, we utilize the dual atom interferometer as a gradiometer for precise gravitational measurements.
View details for DOI 10.1103/PhysRevLett.118.183602
View details for Web of Science ID 000400672600002
View details for PubMedID 28524681
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Resonant mode for gravitational wave detectors based on atom interferometry
PHYSICAL REVIEW D
2016; 94 (10)
View details for DOI 10.1103/PhysRevD.94.104022
View details for Web of Science ID 000387393200005
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Atom-interferometric gravitational-wave detection using heterodyne laser links
PHYSICAL REVIEW A
2016; 94 (3)
View details for DOI 10.1103/PhysRevA.94.033632
View details for Web of Science ID 000384060700009
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Kovachy et al. reply.
Nature
2016; 537 (7618): E2-3
View details for DOI 10.1038/nature19109
View details for PubMedID 27582226
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Quantum superposition at the half-metre scale
NATURE
2015; 528 (7583): 530-?
View details for DOI 10.1038/nature16155
View details for Web of Science ID 000366991900047
View details for PubMedID 26701053
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Matter wave lensing to picokelvin temperatures.
Physical review letters
2015; 114 (14): 143004-?
Abstract
Using a matter wave lens and a long time of flight, we cool an ensemble of ^{87}Rb atoms in two dimensions to an effective temperature of less than 50_{-30}^{+50} pK. A short pulse of red-detuned light generates an optical dipole force that collimates the ensemble. We also report a three-dimensional magnetic lens that substantially reduces the chemical potential of evaporatively cooled ensembles with a high atom number. By observing such low temperatures, we set limits on proposed modifications to quantum mechanics in the macroscopic regime. These cooling techniques yield bright, collimated sources for precision atom interferometry.
View details for PubMedID 25910118
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Enhanced Atom Interferometer Readout through the Application of Phase Shear
PHYSICAL REVIEW LETTERS
2013; 111 (11)
Abstract
We present a method for determining the phase and contrast of a single shot of an atom interferometer. The application of a phase shear across the atom ensemble yields a spatially varying fringe pattern at each output port, which can be imaged directly. This method is broadly relevant to atom-interferometric precision measurement, as we demonstrate in a 10 m ^{87}Rb atomic fountain by implementing an atom-interferometric gyrocompass with 10 mdeg precision.
View details for DOI 10.1103/PhysRevLett.111.113002
View details for Web of Science ID 000324233400007
View details for PubMedID 24074082
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Multiaxis inertial sensing with long-time point source atom interferometry.
Physical review letters
2013; 111 (8): 083001-?
Abstract
We show that light-pulse atom interferometry with atomic point sources and spatially resolved detection enables multiaxis (two rotation, one acceleration) precision inertial sensing at long interrogation times. Using this method, we demonstrate a light-pulse atom interferometer for ^{87}Rb with 1.4 cm peak wave packet separation and a duration of 2T=2.3 s. The inferred acceleration sensitivity of each shot is 6.7×10^{-12}g, which improves on previous limits by more than 2 orders of magnitude. We also measure Earth's rotation rate with a precision of 200 nrad/s.
View details for PubMedID 24010433
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New method for gravitational wave detection with atomic sensors.
Physical review letters
2013; 110 (17): 171102-?
Abstract
Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long baselines and which is immune to laser frequency noise. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultrasensitive gravimeters and gravity gradiometers.
View details for PubMedID 23679702
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Generation of 43 W of quasi-continuous 780 nm laser light via high-efficiency, single-pass frequency doubling in periodically poled lithium niobate crystals
OPTICS LETTERS
2012; 37 (18): 3861-3863
Abstract
We demonstrate high-efficiency frequency doubling of the combined output of two 1560 nm 30 W fiber amplifiers via single pass through periodically poled lithium niobate (PPLN) crystals. The temporal profile of the 780 nm output is controlled by adjusting the relative phase between the seeds of the amplifiers. We obtain a peak power of 34 W of 780 nm light by passing the combined output through one PPLN crystal, and a peak power of 43 W by passing through two cascading PPLN crystals. This source provides high optical power, excellent beam quality and spectral purity, and agile frequency and amplitude control in a simple and compact setup, which is ideal for applications such as atom optics using Rb atoms.
View details for Web of Science ID 000309046300041
View details for PubMedID 23041884
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A high-performance magnetic shield with large length-to-diameter ratio
REVIEW OF SCIENTIFIC INSTRUMENTS
2012; 83 (6)
Abstract
We have demonstrated a 100-fold improvement in the magnetic field uniformity on the axis of a large aspect ratio, cylindrical, mumetal magnetic shield by reducing discontinuities in the material of the shield through the welding and re-annealing of a segmented shield. The three-layer shield reduces Earth's magnetic field along an 8 m region to 420 μG (rms) in the axial direction, and 460 and 730 μG (rms) in the two transverse directions. Each cylindrical shield is a continuous welded tube which has been annealed after manufacture and degaussed in the apparatus. We present both experiments and finite element analysis that show the importance of uniform shield material for large aspect ratio shields, favoring a welded design over a segmented design. In addition, we present finite element results demonstrating the smoothing of spatial variations in the applied magnetic field by cylindrical magnetic shields. Such homogenization is a potentially useful feature for precision atom interferometric measurements.
View details for DOI 10.1063/1.4720943
View details for Web of Science ID 000305833100056
View details for PubMedID 22755663
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Reply to "Comment on 'Atomic gravitational wave interferometric sensor'"
PHYSICAL REVIEW D
2011; 84 (2)
View details for DOI 10.1103/PhysRevD.84.028102
View details for Web of Science ID 000293182400006
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An atomic gravitational wave interferometric sensor in low earth orbit (AGIS-LEO)
GENERAL RELATIVITY AND GRAVITATION
2011; 43 (7): 1953-2009
View details for DOI 10.1007/s10714-011-1182-x
View details for Web of Science ID 000291059400005
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Precision angle sensor using an optical lever inside a Sagnac interferometer
OPTICS LETTERS
2011; 36 (9): 1698-1700
Abstract
We built an ultra-low-noise angle sensor by combining a folded optical lever and a Sagnac interferometer. The instrument has a measured noise floor of 1.3 prad/√Hz at 2.4 kHz. We achieve this record angle sensitivity using a proof-of-concept apparatus with a conservative N=11 bounces in the optical lever. This technique could be extended to reach subpicoradian/√Hz sensitivities with an optimized design.
View details for Web of Science ID 000290037300058
View details for PubMedID 21540973
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Picosecond Optical Switching Using RF Nonlinear Transmission Lines
JOURNAL OF LIGHTWAVE TECHNOLOGY
2011; 29 (5): 666-669
View details for DOI 10.1109/JLT.2010.2103301
View details for Web of Science ID 000296695800003
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Optical lattices as waveguides and beam splitters for atom interferometry: An analytical treatment and proposal of applications
PHYSICAL REVIEW A
2010; 82 (1)
View details for DOI 10.1103/PhysRevA.82.013638
View details for Web of Science ID 000280364200011
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Broadband optical serrodyne frequency shifting
OPTICS LETTERS
2010; 35 (5): 745-747
Abstract
We demonstrate serrodyne frequency shifting of light from 200 MHz to 1.2 GHz with an efficiency of better than 60%. The frequency shift is imparted by an electro-optic phase modulator driven by a high-frequency high-fidelity sawtooth waveform that is passively generated by a commercially available nonlinear transmission line. We also implement a push-pull configuration using two serrodyne-driven phase modulators, allowing for continuous tuning between -1.6 GHz and +1.6 GHz. Compared with competing technologies, this technique is simple and robust, and it offers the largest available tuning range in this frequency band.
View details for Web of Science ID 000275826700044
View details for PubMedID 20195339
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Gravitational wave detection with atom interferometry
PHYSICS LETTERS B
2009; 678 (1): 37-40
View details for DOI 10.1016/j.physletb.2009.06.011
View details for Web of Science ID 000267816100006
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Atomic gravitational wave interferometric sensor
PHYSICAL REVIEW D
2008; 78 (12)
View details for DOI 10.1103/PhysRevD.78.122002
View details for Web of Science ID 000262251100003
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General relativistic effects in atom interferometry
PHYSICAL REVIEW D
2008; 78 (4)
View details for DOI 10.1103/PhysRevD.78.042003
View details for Web of Science ID 000259368500007
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How to test atom and neutron neutrality with atom interferometry
PHYSICAL REVIEW LETTERS
2008; 100 (12)
Abstract
We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{-28}e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{-28}e, 7 orders of magnitude below current bounds.
View details for DOI 10.1103/PhysRevLett.100.120407
View details for Web of Science ID 000254473800007
View details for PubMedID 18517846
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Testing general relativity with atom interferometry
PHYSICAL REVIEW LETTERS
2007; 98 (11)
Abstract
The unprecedented precision of atom interferometry will soon lead to laboratory tests of general relativity to levels that will rival or exceed those reached by astrophysical observations. We propose such an experiment that will initially test the equivalence principle to 1 part in 10(15) (300 times better than the current limit), and 1 part in 10(17) in the future. It will also probe general relativistic effects - such as the nonlinear three-graviton coupling, the gravity of an atom's kinetic energy, and the falling of light - to several decimals. In contrast with astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables.
View details for DOI 10.1103/PhysRevLett.98.111102
View details for Web of Science ID 000244959300014
View details for PubMedID 17501039