Abstract: Various embodiments of a modular unit for a topologic qubit and of scalable quantum computing architectures using such modular units are disclosed herein. For example, one example embodiment is a modular unit for a topological qubit comprising 6 Majorana zero modes (MZMs) on a mesoscopic superconducting island. These units can provide the computational MZMs with protection from quasiparticle poisoning. Several possible realizations of these modular units are described herein. Also disclosed herein are example designs for scalable quantum computing architectures comprising the modular units together with gates and reference arms (e.g., quantum dots, Majorana wires, etc.) configured to enable joint parity measurements to be performed for various combinations of two or four MZMs associated with one or two modular units, as well as other operations on the states of MZMs.

Abstract: Among the embodiments disclosed herein are example methods for generating all Clifford gates for a system of Majorana Tetron qubits (quasiparticle poisoning protected) given the ability to perform certain 4 Majorana zero mode measurements. Also disclosed herein are example designs for scalable quantum computing architectures that enable the methods for generating the Clifford gates, as well as other operations on the states of MZMs. These designs are configured in such a way as to allow the generation of all the Clifford gates with topological protection and non-Clifford gates (e.g. a ?/8-phase gate) without topological protection, thereby producing a computationally universal gate set. Several possible realizations of these architectures are disclosed.

Abstract: Embodiments of the disclosed technology comprise methods and/or devices for performing measurements and/or manipulations of the collective state of a set of Majorana quasiparticles/Majorana zero modes (MZMs). Example methods/devices utilize the shift of the combined energy levels due to coupling multiple quantum systems (e.g., in a Stark-effect-like fashion). The example methods can be used for performing measurements of the collective topological charge or fermion parity of a group of MZMs (e.g., a pair of MZMs or a group of 4 MZMs). The example devices can be utilized in any system supporting MZMs.

Abstract: Various embodiments of a modular unit for a topologic qubit and of scalable quantum computing architectures using such modular units are disclosed herein. For example, one example embodiment is a modular unit for a topological qubit comprising 6 Majorana zero modes (MZMs) on a mesoscopic superconducting island. These units can provide the computational MZMs with protection from quasiparticle poisoning. Several possible realizations of these modular units are described herein. Also disclosed herein are example designs for scalable quantum computing architectures comprising the modular units together with gates and reference arms (e.g., quantum dots, Majorana wires, etc.) configured to enable joint parity measurements to be performed for various combinations of two or four MZMs associated with one or two modular units, as well as other operations on the states of MZMs.

Abstract: Among the embodiments disclosed herein are example methods for generating all Clifford gates for a system of Majorana Tetron qubits (quasiparticle poisoning protected) given the ability to perform certain 4 Majorana zero mode measurements. Also disclosed herein are example designs for scalable quantum computing architectures that enable the methods for generating the Clifford gates, as well as other operations on the states of MZMs. These designs are configured in such a way as to allow the generation of all the Clifford gates with topological protection and non-Clifford gates (e.g. a ?/8-phase gate) without topological protection, thereby producing a computationally universal gate set. Several possible realizations of these architectures are disclosed.