Abstract: A Heisenberg scaler reduces noise in quantum metrology and includes: a stimulus source that provides physical stimuli; a physical system including quantum sensors that receive a first and second physical stimuli; produces a measured action parameter; receives an perturbation pulse; and produces modal amplitude; an estimation machine that: receives the measured action parameter and produces a zeroth-order value from the measured action parameter; a gradient analyzer that: receives the measured action parameter and produces the measured action parameter and a gradient; the sensor interrogation unit that: receives the modal amplitude; receives the gradient and the measured action parameter; produces the perturbation pulse; and produces a first-order value from the modal amplitude, the gradient, and the measured action parameter; a Heisenberg determination machine that: receives the zeroth-order value; receives the first-order value; and produces a physical scalar from the zeroth-order value and the first-order v

Abstract: Performing state reversal on a quantum spin chain includes: providing qubits in a quantum spin chain in an input state, such that the quantum spin chain includes: first and second terminal qubits and one or more intermediate qubits, such that: the qubits have a transverse field strength; the first and terminal qubits a longitudinal field strength; and nearest neighbor qubit pair has an Ising coupling strength; and evolving the quantum spin chain from the input state to a final state for an evolution period to perform state reversal on the quantum spin chain.

Abstract: A method for quantum state transfer includes iteratively expanding an initial quantum state from an initial qudit, of a plurality of qudits, over a sequence of expanding domains. For each iteration, a quantum circuit is applied to the qudits belonging to a respective domain of the sequence. The quantum circuit transforms the qudits of the respective domain into an intermediate quantum state that includes a W state formed with the qudits of the respective domain. The last iteration generates a maximally expanded state. The method may also include iteratively compressing the maximally expanded state according to a sequence of contacting domains. After compressing, a final qudit, of the plurality of qudits, is in a final quantum state that approximates the initial quantum state.

Abstract: Preparing a metrologically-relevant entangled state includes: providing a plurality of atoms in a regular lattice, wherein each atom is in an initial quantum state of a first state in a ground state manifold; initializing a central atom in the regular lattice to a (|0+|1)/?2 state while all other atoms remain in the first state |0 as remaining atoms; and proceeding, starting with the central atom, to propagate preparation of Greenberger-Horne-Zeilinger (GHZ) states in a nonlinear progression by increasing a number of GHZ states in each iteration through the remaining atoms in a recursive manner, to produce an intermediate GHZ state, such that the intermediate GHZ state acts as an initial GHZ state for a next iteration, until a final GHZ state is formed to prepare the metrologically-relevant entangled state of the atoms.

Abstract: A Heisenberg scaler reduces noise in quantum metrology and includes: a stimulus source that provides physical stimuli; a physical system including quantum sensors that receive a first and second physical stimuli; produces a measured action parameter; receives an perturbation pulse; and produces modal amplitude; an estimation machine that: receives the measured action parameter and produces a zeroth-order value from the measured action parameter; a gradient analyzer that: receives the measured action parameter and produces the measured action parameter and a gradient; the sensor interrogation unit that; receives the modal amplitude; receives the gradient and the measured action parameter produces the perturbation pulse; and produces a first-order value from the modal amplitude, the gradient, and the measured action parameter; a Heisenberg determination machine that: receives the zeroth-order value; receives the first-order value; and produces a physical scalar from the zeroth-order value and the first-order va