Josephson constant
E160623
The Josephson constant is a fundamental physical constant that relates frequency to voltage in superconducting Josephson junctions and underpins the quantum standard of voltage.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Josephson constant canonical | 5 |
| Josephson relations | 1 |
| Josephson voltage-frequency relation | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1403716 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Josephson constant Context triple: [CODATA recommended values of the fundamental physical constants, includesConstant, Josephson constant]
-
A.
Planck constant
The Planck constant is a fundamental physical constant that quantifies the relationship between the energy of a photon and the frequency of its associated electromagnetic wave, forming a cornerstone of quantum mechanics.
-
B.
Boltzmann constant
The Boltzmann constant is a fundamental physical constant that links temperature to energy at the particle level, playing a central role in statistical mechanics and thermodynamics.
-
C.
Fermi constant
The Fermi constant is a fundamental physical constant that quantifies the strength of the weak nuclear force in processes such as beta decay.
-
D.
Faraday constant
The Faraday constant is a fundamental physical constant representing the electric charge carried by one mole of electrons, widely used in electrochemistry and physics.
-
E.
Planck units
Planck units are a system of natural units in physics where fundamental constants like the speed of light, gravitational constant, and Planck constant are normalized to 1, providing a scale-free framework for describing physical laws.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Josephson constant Target entity description: The Josephson constant is a fundamental physical constant that relates frequency to voltage in superconducting Josephson junctions and underpins the quantum standard of voltage.
-
A.
Planck constant
The Planck constant is a fundamental physical constant that quantifies the relationship between the energy of a photon and the frequency of its associated electromagnetic wave, forming a cornerstone of quantum mechanics.
-
B.
Boltzmann constant
The Boltzmann constant is a fundamental physical constant that links temperature to energy at the particle level, playing a central role in statistical mechanics and thermodynamics.
-
C.
Fermi constant
The Fermi constant is a fundamental physical constant that quantifies the strength of the weak nuclear force in processes such as beta decay.
-
D.
Faraday constant
The Faraday constant is a fundamental physical constant representing the electric charge carried by one mole of electrons, widely used in electrochemistry and physics.
-
E.
Planck units
Planck units are a system of natural units in physics where fundamental constants like the speed of light, gravitational constant, and Planck constant are normalized to 1, providing a scale-free framework for describing physical laws.
- F. None of above. chosen
Statements (30)
| Predicate | Object |
|---|---|
| instanceOf |
fundamental constant
ⓘ
physical constant ⓘ |
| appearsIn | Josephson effect ⓘ |
| appliesTo | superconducting Josephson junctions ⓘ |
| category | electromagnetic constant ⓘ |
| CODATA2018RelativeStandardUncertainty | 0 (exact, from defined e and h) ⓘ |
| CODATA2018Value | 483597.8484 × 10^9 Hz·V⁻¹ ⓘ |
| defines | relationship between frequency and voltage in Josephson junctions ⓘ |
| dependsOn |
Planck constant
ⓘ
elementary charge ⓘ |
| governs |
V = (h/2e) f relation in Josephson junctions
ⓘ
voltage steps in Shapiro steps ⓘ |
| hasDimension | T·Q⁻¹ (time per electric charge) ⓘ |
| hasFormula | K_J = 2e/h ⓘ |
| isExactSince | 2019 SI redefinition ⓘ |
| namedAfter |
Brian D. Josephson
ⓘ
linked to:
Brian David Josephson
|
| partOf | system of constants defining SI units after 2019 redefinition ⓘ |
| relatedEffect |
AC Josephson effect
ⓘ
DC Josephson effect ⓘ
linked to:
Josephson effect
|
| relatedQuantity | von Klitzing constant ⓘ |
| relates | microwave frequency to DC voltage ⓘ |
| roleIn | realization of the volt ⓘ |
| SIUnit | hertz per volt ⓘ |
| SIUnitSymbol | Hz·V⁻¹ ⓘ |
| symbol | K_J ⓘ |
| usedBy | metrology laboratories ⓘ |
| usedIn |
Josephson voltage standard
ⓘ
calibration of voltage references ⓘ precision measurements of fundamental constants ⓘ quantum standard of voltage ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Josephson constant Description of subject: The Josephson constant is a fundamental physical constant that relates frequency to voltage in superconducting Josephson junctions and underpins the quantum standard of voltage.
Referenced by (7)
Full triples — surface form annotated when it differs from this entity's canonical label.
CODATA recommended values of the fundamental physical constants
→
includesConstant
→
Josephson constant
ⓘ
linked to: Josephson constant