Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A Macroscopic Mass From Quantum Behavior In An Integrated Approach



Frank Seifert, Alireza Panna, Lorenz Keck, Leon Chao, Shamith Payagala, Dean G. Jarrett, Dipanjan Saha, Randolph Elmquist, Stephan Schlamminger, Albert Rigosi, David B. Newell, Darine El Haddad


The revision of the International System of Units (SI) on May 20th, 2019, has enabled new improved experiments to consolidate and simplify electrical and mechanical metrology currently underway. Historically within the SI, the definition of energy was only available in the mechanical realm as where the units of mass, time, and length were given. Consequently, electrical units could only be defined via complicated mechanical experiments. Previously, the ampere was defined as the current flowing between two parallel wires producing a well defined force between them, an abstraction that was difficult to realize experimentally. With the advent of quantum electrical standards, specifically the prediction of the Josephson effect by B. Josephson in 1962 [1], and the discovery of the quantum Hall effect by K. v. Klitzing in 1980 [2], the mechanical realization of electrical units ceased, and electrical units became disjointed from the SI, and were used as "conventional" units internationally. The revision in 2019 removed this dichotomy and consolidated our system of units. The mechanical unit of mass is defined via electrical power using the Josephson and the quantum Hall effect. While the Kibble balance has successfully rationalized the unit of mass, the kilogram, it has never done so in a single experimental setup. Typically, the von Klitzing constant is realized in a separate experiment and used in the Kibble balance via a traditional transfer standard, a wire or thin film resistor. Here, we present the direct connection between a macroscopic mass and the defined electrical power in a single experiment, in which the current used to levitate a 100 g mass passes through a graphene quantum Hall standard. The Josephson effect voltage is compared directly to the resulting quantum Hall effect voltage. These results mark a significant progress in both Kibble balance design as well as the use of graphene arrays for scaling in resistance with improved uncertainty and higher current level
Nature Communications Physics


Quantum Hall Array, graphene, mass, kibble balance, SI


Seifert, F. , Panna, A. , Keck, L. , Chao, L. , Payagala, S. , Jarrett, D. , Saha, D. , Elmquist, R. , Schlamminger, S. , Rigosi, A. , Newell, D. and El Haddad, D. (2022), A Macroscopic Mass From Quantum Behavior In An Integrated Approach, Nature Communications Physics, [online],, (Accessed July 14, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created December 10, 2022, Updated January 23, 2023