Abstract: A charged particle trap is disclosed. The charged particle trap comprises a substrate and a layer structure disposed on the substrate, the layer structure including an antenna layer and an electrode layer. The antenna layer comprises a co-planar conductive meander line comprising at least three elongate arms which are parallel and co-planar, and which are symmetrical about a central axis. The electrode layer comprises a set of electrodes arranged to trap charged particles along a trap axis which is parallel to the central axis and to generate a pseudopotential which is symmetrical about the trap axis.

Abstract: A method of operating a charged particle trap which includes a set of trap electrodes. The method comprise trapping a first charged particle at a first position, the first charged particle providing a first qubit having a first transition frequency and trapping a second charged particle, at a second position, the second charged particle providing a second qubit having a second transition frequency. The method comprises applying a potential gradient to the first and second charged particles, wherein the first and second charged particles experience first and second magnitudes of potential gradient, respectively, and wherein the potential gradient oscillates at a given frequency and is monochromatic.

Abstract: A quantum information processing system is disclosed. The system comprises a charged particle trap comprising a substrate and a set of electrodes supported on the substrate, and a control system for controlling the charged particle trap, for applying biases to the set of electrodes for trapping at least one charged particle and performing at least one quantum logic gate on the at least one charged particle. The electrodes include at least one current-carrying electrode which is formed of a superconducting material. The control system is configured to pass a current through the at least one current-carrying electrode having a peak current of at least 1 A.

Abstract: A computer implemented method (200) comprising selecting one or more pairs of energy levels of an isotope of an ion for a qubit for a quantum computer, wherein each of the one or more pairs of energy levels comprises a first metastable state and a second metastable state.

Abstract: A method is presented, which includes trapping a charged particle at a first position using an electromagnetic trap and providing a static magnetic field at the first position such that a qubit transition of the charged particle is defined, and providing, using an entangling electrode, an oscillating magnetic field. The oscillating magnetic field present at the first position does not contain a polarisation component which directly couples to the qubit transition. The oscillating magnetic field has a spatial gradient at the first position, of the polarisation component of the oscillating magnetic field which couples the qubit transition to the motion of the charged particle.

Abstract: A micro-fabricated device for controlling trapped ions includes a substrate of a dielectric material or a semiconductor material. A structured electrode layer is disposed above the substrate. The structured electrode layer forms a plurality of electrodes of an ion trap configured to trap ions in a space above the structured electrode layer. The structured electrode layer includes a low phonon density of states layer, referred to as low-PDOS layer, the low-PDOS layer being of TiN or TiW or Ti or W and having a thickness of equal to or greater than 100 nm.

Abstract: A method is presented, which includes trapping a charged particle at a first position using an electromagnetic trap and providing a static magnetic field at the first position such that a qubit transition of the charged particle is defined, and providing, using an entangling electrode, an oscillating magnetic field. The oscillating magnetic field present at the first position does not contain a polarisation component which directly couples to the qubit transition. The oscillating magnetic field has a spatial gradient at the first position, of the polarisation component of the oscillating magnetic field which couples the qubit transition to the motion of the charged particle.