Experimental Upper Limit on the Magnetic Monopole Moment of Electrons, Protons, and Neutrons, Utilizing a Superconducting Quantum Interferometer

Small Magnetic Charges and Monopoles in Nonassociative Quantum Mechanics

“…Using the basic commutation relation ofq andp, such products can always be rewritten as sums over individualT m ′′ ,n ′′ of order m + n + m ′ + n ′ or less, as derived explicitly in [17]. The condition (27) is therefore equivalent to a recurrence relation for T m,n E which is shown and discussed in more detail in our supplementary material. (This material also uses an algebraic notion of states [18] and makes contact with effective constraints [19,20].…”

“…The algebraic notion, however, can also be used in cases without a Hilbert space, as in non-associative quantum mechanics. As in the letter, we define an energy eigenstate Ω E ofĤ with eigenvalue E by the condition Ω E (â(Ĥ − E)) = 0 (27) for all algebra elementsâ, or all polynomials inq andp. Following [15,16], we define the algebra elementŝ T m,n := (q mpn ) Weyl where m and n are non-negative integers, and the subscript indicates that the product is taken in the totally symmetric ordering.…”

Superconducting magnetometers

“…The present sensitivity and response time of these instruments make them appropriate research tools for a diversity of experiments. Our use has ranged from determination of magnetic susceptibility [18] and measurements of fundamental constants [19] to a search for magnetic monopoles [20].…”

Limits on Non-Linear Electrodynamics

“…From an experimental point of view, limits exist for electron and proton magnetic charge [36,43]. The electron magnetic charge Q M , inducing a Coulomb magnetic field B = Q M /4πr 2 e r , has been found to be : This corresponds to :…”