dwave.system.temperatures.h_to_fluxbias#

h_to_fluxbias(h: float | ndarray = 1, Ip: float | None = None, B: float = 1.391, MAFM: float | None = 1.647, units_Ip: str | None = 'uA', units_B: str = 'GHz', units_MAFM: str | None = 'pH') → float | ndarray[source]#

Convert problem Hamiltonian bias h to equivalent flux bias.

Unitless bias h is converted to the equivalent flux bias in units \(\Phi_0\), the magnetic flux quantum.

The dynamics of h and flux bias differ, as described in the Ip_in_units_of_B() function. Equivalence at a specific point in the anneal is valid under a freeze-out (quasi-static) hypothesis.

Defaults are based on the published physical properties of Leap‘s Advantage_system4.1 solver at single-qubit freezeout (\(s=0.612\)).

Parameters:

  • Ip – Persistent current, \(I_p(s)\), in units of amps or microamps. When not provided, inferred from \(M_{AFM}\) and and \(B(s)\) based on the relation \(B(s) = 2 M_{AFM} I_p(s)^2\).

  • B – Annealing schedule field, \(B(s)\), associated with the problem Hamiltonian. Schedules are provided for each quantum computer in the system documentation. This parameter is ignored when Ip is specified.

  • MAFM – Mutual inductance, \(M_{AFM}\), specified for each quantum computer in the system documentation. MAFM is ignored when Ip is specified.

  • units_Ip – Units in which the persistent current, Ip, is specified. Allowed values are 'uA' (microamps) and 'A' (amps)

  • units_B – Units in which the schedule B is specified. Allowed values are 'GHz' (gigahertz) and 'J' (Joules).

  • units_MAFM – Units in which the mutual inductance, MAFM, is specified. Allowed values are 'pH' (picohenry) and 'H' (Henry).

Returns:

Flux-bias values producing equivalent longitudinal fields to the given h values.