Test of general relativity by a pair of transportable optical lattice clocks

Published on Apr 6, 2020in Nature Photonics38.771
· DOI :10.1038/S41566-020-0619-8
Masao Takamoto24
Estimated H-index: 24
,
Ichiro Ushijima9
Estimated H-index: 9
(UTokyo: University of Tokyo)
+ 4 AuthorsHidetoshi Katori39
Estimated H-index: 39
(UTokyo: University of Tokyo)
Sources
Abstract
A clock at a higher altitude ticks faster than one at a lower altitude, in accordance with Einstein’s theory of general relativity. The outstanding stability and accuracy of optical clocks, at 10−18 levels1–5, allows height differences6 of a centimetre to be measured. However, such state-of-the-art clocks have been demonstrated only in well-conditioned laboratories. Here, we demonstrate an 18-digit-precision frequency comparison in a broadcasting tower, Tokyo Skytree, by developing transportable optical lattice clocks. The tower provides the clocks with adverse conditions to test the robustness and a 450 m height difference to test the gravitational redshift at (1.4 ± 9.1) × 10−5. The result improves ground-based clock comparisons7–9 by an order of magnitude and is comparable with space experiments10,11. Our demonstration shows that optical clocks resolving centimetres are technically ready for field applications, such as monitoring spatiotemporal changes of geopotentials caused by active volcanoes or crustal deformation12 and for defining the geoid13,14, which will have an immense impact on future society. A pair of transportable optical lattice clocks with 10−18 uncertainty is developed. The relativistic redshift predicted by the theory of general relativity has been tested at the 10–5 level by the two optical clocks with a height difference of 450 m on the ground.
📖 Papers frequently viewed together
24 Authors (Jacopo Grotti, ..., Davide Calonico)
20193.16Metrologia
8 Authors (Tobias Bothwell, ..., Colin Kennedy)
201849.96Nature
12 Authors (W. F. McGrew, ..., Andrew D. Ludlow)
References38
Newest
#1Samuel M. Brewer (CU: University of Colorado Boulder)H-Index: 11
#2Jwo-Sy Chen (NIST: National Institute of Standards and Technology)H-Index: 9
Last. David R. Leibrandt (NIST: National Institute of Standards and Technology)H-Index: 24
view all 8 authors...
We describe an optical atomic clock based on quantum-logic spectroscopy of the ^1_0\leftrightarrow^3_0transition in ^{27}l^{+}with a systematic uncertainty of {9.4 \times 10^{-19}}and a frequency stability of {1.2\times10^{-15}/\sqrt{\tau}} A ^{25}g^{+}ion is simultaneously trapped with the ^{27}l^{+}ion and used for sympathetic cooling and state readout. Improvements in a new trap have led to reduced secular motion heating, compared to previous ^{27}l$^...
Source
#1B. X. R. Alves (University of Paris)H-Index: 1
#2Y. Foucault (University of Paris)H-Index: 1
Last. Jérôme Lodewyck (University of Paris)H-Index: 24
view all 4 authors...
Collisional induced frequency shift due to background gas are currently known only theoretically. However, we show that the this source of systematic uncertainty is at the level of 1017 for cold strontium atoms trapped in an optical lattice, and cannot be neglected in the accuracy budget calculation. Furhter measurements are being performed in order to better understand how to precisely account for this effect.
Source
#1Christian Sanner (JILA)H-Index: 19
#2Nils Huntemann (German National Metrology Institute)H-Index: 17
Last. Sergey G. Porsev (UD: University of Delaware)H-Index: 33
view all 7 authors...
Questioning basic assumptions about the structure of space and time has greatly enhanced our understanding of nature. State-of-the-art atomic clocks1–3 make it possible to precisely test fundamental symmetry properties of spacetime and search for physics beyond the standard model at low energies of just a few electronvolts4. Modern tests of Einstein’s theory of relativity try to measure so-far-undetected violations of Lorentz symmetry5; accurately comparing the frequencies of optical clocks is a...
Source
#1Ichiro Ushijima (UTokyo: University of Tokyo)H-Index: 9
#2Masao TakamotoH-Index: 24
Last. Hidetoshi Katori (UTokyo: University of Tokyo)H-Index: 39
view all 3 authors...
: We experimentally investigate the lattice-induced light shift by the electric-quadrupole (E2) and magnetic-dipole (M1) polarizabilities and the hyperpolarizability in Sr optical lattice clocks. Precise control of the axial as well as the radial motion of atoms in a one-dimensional lattice allows observing the E2-M1 polarizability difference. Measured polarizabilities determine an operational lattice depth to be 72(2)E_{R}, where the total light shift cancels to the 10^{-19} level, over a latti...
Source
#1Sven Herrmann (University of Bremen)H-Index: 29
#2Felix Finke (University of Bremen)H-Index: 2
Last. Claus Lämmerzahl (University of Bremen)H-Index: 35
view all 17 authors...
On August 22, 2014, the satellites GSAT-0201 and GSAT-0202 of the European GNSS Galileo were unintentionally launched into eccentric orbits. Unexpectedly, this has become a fortunate scientific opportunity since the onboard hydrogen masers allow for a sensitive test of the redshift predicted by the theory of general relativity. In the present Letter we describe an analysis of approximately three years of data from these satellites including three different clocks. For one of these we determine t...
Source
#1P. Delva (University of Paris)H-Index: 8
#2N. Puchades (University of Paris)H-Index: 1
Last. Peter Wolf (University of Paris)H-Index: 22
view all 14 authors...
We report on a new test of the gravitational redshift and thus of local position invariance, an integral part of the Einstein equivalence principle, which is the foundation of general relativity and all metric theories of gravitation. We use data spanning 1008 days from two satellites of Galileo, Europe's global satellite navigation system (GNSS), which were launched in 2014, but accidentally delivered on elliptic rather than circular orbits. The resulting modulation of the gravitational redshif...
Source
#1Piotr Wcisło (UMK: Nicolaus Copernicus University in Toruń)H-Index: 18
#2P. Ablewski (UMK: Nicolaus Copernicus University in Toruń)H-Index: 8
Last. Michal Zawada (UMK: Nicolaus Copernicus University in Toruń)H-Index: 17
view all 22 authors...
We report on the first Earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the fine-structure constant of essential parts of an optical atomic clock, i.e., the cold atoms and the optical reference cavity, we can perform sensitive searches for DM signatures without the need for real-time comparisons of the clocks. We report a two orders of magnitude improvement in constraints on transient variatio...
Source
#1Stefano Origlia (HHU: University of Düsseldorf)H-Index: 3
#2M. S. Pramod (HHU: University of Düsseldorf)H-Index: 5
Last. Ch. Lisdat (German National Metrology Institute)H-Index: 18
view all 12 authors...
Optical clocks operated on satellites are expected to open up new opportunities in time transfer, geodesy, fundamental physics, and satellite navigation. Here we demonstrate an important first step towards this goal: a modular, compact, optical lattice clock (OLC) system that achieves 2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}fractional uncertainty. The clock is operated with bosonic strontium and improves the performance of bosonic OLCs by a factor of 30. This has important...
Source
#1W. F. McGrew (CU: University of Colorado Boulder)H-Index: 9
#2Xiaogang Zhang (PKU: Peking University)H-Index: 12
Last. Andrew D. Ludlow (CU: University of Colorado Boulder)H-Index: 43
view all 12 authors...
The passage of time is tracked by counting oscillations of a frequency reference, such as Earth’s revolutions or swings of a pendulum. By referencing atomic transitions, frequency (and thus time) can be measured more precisely than any other physical quantity, with the current generation of optical atomic clocks reporting fractional performance below the 10−17 level1–5. However, the theory of relativity prescribes that the passage of time is not absolute, but is affected by an observer’s referen...
Source
#1Christian SannerH-Index: 19
#2Nils HuntemannH-Index: 17
Last. Sergey G. PorsevH-Index: 33
view all 7 authors...
Questioning the presumably most basic assumptions about the structure of space and time has revolutionized our understanding of Nature. State-of-the-art atomic clocks make it possible to precisely test fundamental symmetry properties of spacetime, and search for physics beyond the standard model at low energy scales of just a few electron volts. Here, we experimentally demonstrate for the first time agreement of two single-ion clocks at the 10^{-18}level and directly confirm the validity of t...
Source
Cited By93
Newest
#1Jaewon Yang (KAIST)H-Index: 15
#2Hyun Jay Kang (KAIST)H-Index: 4
Last. Seung-Woo Kim (KAIST)H-Index: 33
view all 6 authors...
Abstract null null Optical frequency transfer through the atmosphere is needed for diverse free-space applications, e.g. coherent communication, optical clock comparison and relativity experiments. The task requires an appropriate optical link system that provides the multimodal abilities of not only pointing, acquisition, and tracking (PAT) but also phase noise suppression in the presence of air turbulence. Here, we describe a free-space optical (FSO) link system built over a 1.4 km outdoor pat...
Source
#1Fabio Di PumpoH-Index: 4
#2Christian UfrechtH-Index: 6
Last. William G. UnruhH-Index: 49
view all 6 authors...
Atomic interference experiments can probe the gravitational redshift via the internal energy splitting of atoms and thus give direct access to test the universality of the coupling between matter-energy and gravity at different spacetime points. By including possible violations of the equivalence principle in a fully quantized treatment of all degrees of freedom, we characterize how the sensitivity to gravitational redshift violations arises in atomic clocks and atom interferometers, as well as ...
Source
#1A. Golovizin (FIAN: Lebedev Physical Institute)H-Index: 4
#2D. O. Tregubov (FIAN: Lebedev Physical Institute)H-Index: 8
Last. Nikolai N. Kolachevsky (FIAN: Lebedev Physical Institute)H-Index: 19
view all 5 authors...
We have developed a compact vacuum system for laser cooling and spectroscopy of neutral thulium atoms. Compactness is achieved by obviating a classical Zeeman slower section and placing an atomic oven close to a magneto-optical trap (MOT), specifically at the distance of 11 cm. In this configuration, we significantly gained in solid angle of an atomic beam, which is affected by MOT laser beams, and reached 1 million atoms loaded directly in the MOT with only 15 mW of MOT cooling beams net power....
Source
#1Huidong KimH-Index: 4
#2Myoung-Sun HeoH-Index: 7
Last. Won-Kyu LeeH-Index: 16
view all 5 authors...
We report a measurement of the absolute frequency of the 1S0-3P0 transition in the 171Yb optical lattice clock at KRISS (KRISS-Yb1) for 14 months, which was referenced to the SI second by primary and secondary standards worldwide via TAI (International Atomic Time). The determined absolute frequency is 518 295 836 590 863.75(14) Hz with the relative frequency uncertainty of 2.6x10^-16, which agrees well with other reports. This result is expected to contribute to the future update of the CIPM re...
Source
Abstract null null We propose a novel approach for testing the gravitational redshift based on frequency signals transmitted between a spacecraft and a ground station. The main idea is integrating one uplink signal from ground to spacecraft and two downlink signals from spacecraft to ground. Based on the integration and certain correction models, the gravitational shift of the signals between spacecraft and ground station can be detected at high precision level. The gravitational redshift effect...
Source
We demonstrate a simple and compact approach to laser cool and trap atoms based on laser ablation of a pure solid granule. A rapid thermalisation of the granule leads to a fast recovery of the ultra-high vacuum condition required for a long trapping lifetime of the cold gas. We give a proof-of-concept of the technique, performing a magneto-optical trap on the 461 nm ^1S_0\rightarrow^1P_1transition of strontium. We get up to 3.5 million of cold strontium-88 atoms with a trapping lifetime of mo...
#1Tobias BothwellH-Index: 9
#2Colin KennedyH-Index: 10
Last. Jun YeH-Index: 126
view all 8 authors...
Einstein's theory of general relativity states that clocks at different gravitational potentials tick at different rates - an effect known as the gravitational redshift. As fundamental probes of space and time, atomic clocks have long served to test this prediction at distance scales from 30 centimeters to thousands of kilometers. Ultimately, clocks will study the union of general relativity and quantum mechanics once they become sensitive to the finite wavefunction of quantum objects oscillatin...
#2Ziyu Shen (Huda: Hubei University)H-Index: 2
#3Wenbin Shen (WHU: Wuhan University)H-Index: 16
Last. Yifan Wu (WHU: Wuhan University)H-Index: 1
view all 6 authors...
Abstract null null The development of remote frequency transfer techniques, especially the appearance of optical clocks with unprecedented stability, has prompted geoscientists to study their applications in geodesy. Using remote frequency transfer technique, by frequency comparison of two optical clocks at two points P and Q connected by optical fibers, one can measure the signal's frequency shift between them, and the geopotential difference between them can be determined based on the gravity ...
Source
#1Yifan Wu (WHU: Wuhan University)
#2Wenbin Shen (WHU: Wuhan University)H-Index: 16
Abstract Known for unique ultrahigh spatial resolution and timing accuracy, the VLBI global observing system (VGOS) time transfer of ultralong baselines can achieve better long-term stability compared to other techniques. Because of the 1 mm positioning accuracy of the VGOS, comparing high-performance atomic clocks with VGOS time transfer can be used to accurately determine the geopotential difference between two remote stations and unify the world height system in the framework of the theory of...
Source
Pioneers of mRNA vaccines and next-generation sequencing techniques are among the winners of science’s most lucrative awards. null Pioneers of mRNA vaccines and next-generation sequencing techniques are among the winners of science’s most lucrative awards.
Source
This website uses cookies.
We use cookies to improve your online experience. By continuing to use our website we assume you agree to the placement of these cookies.
To learn more, you can find in our Privacy Policy.