US 10,593,879 B2Granted

Quantum information processing with majorana bound states in superconducting circuits

AssigneeMassachusetts Institute of Technology

InventorsConstantin Schrade, Liang Fu

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Abstract

In a weak link of two s-wave superconductors (SCs) coupled via a time-reversal-invariant (TRI) topological superconducting (TSC) island, a Josephson current can flow due to Cooper pairs tunneling in and out of spatially separated Majorana Kramers pairs (MKPs), which are doublets of Majorana bound states (MBSs). The sign of the resulting Josephson current is fixed by the joint parity of the four Majorana bound states that make up the MKPs on the TSC island. This parity-controlled Josephson effect can be used as a read-out mechanism for the joint parity in Majorana-based quantum computing. For a TSC island with four terminals, the SC leads can address a Majorana superconducting qubit (MSQ) formed by the charge ground states of the TSC island's terminals. Cooper pair splitting enables single-qubit operations, qubit read-out, as well as two-qubit entangling gates. Hence, TSC islands between SC leads may provide an alternative approach to superconducting quantum computation.

Claims11

Dependent claims

A Majorana superconducting device comprising:

a first superconducting lead;
a second superconducting lead;
a topological superconductor (TSC) island, disposed between the first superconducting lead and the second superconducting lead, having a first terminal to host a first Majorana bound state coupled to the first superconducting lead and a second terminal to host a second Majorana bound state coupled to the second superconducting lead;
and
a TSC reference island, disposed between the first superconducting lead and the second superconducting lead, having a first reference terminal to host a first reference Majorana bound state coupled to the first superconducting lead and a second reference terminal to host a second reference Majorana bound state coupled to the second superconducting lead;
and
a measurement device, operably coupled to the first superconducting lead and the second superconducting lead, to measure a sign of a supercurrent traveling through the TSC island and the TSC reference island, the sign of the supercurrent indicating a joint parity of the first Majorana bound state, the second Majorana bound state, the first reference Majorana bound state, and the second reference Majorana bound state.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/244,176Filed 10 Jan 2019 · us provisional application
Priority: 10 Jan 2018
Published: US 2019/0214561 A111 Jul 2019
Granted: 17 Mar 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H10N 60/128
Junction-based devices: having three or more electrodes, e.g. transistor-like structures
H10N 99/03
Subject matter not provided for in other groups of this subclass: devices using Mott metal-insulator transition, e.g. field-effect transistor-like…
B82Y 10/00
Nanotechnology for information processing, storage or transmission
G06N 10/40
Quantum computing, i.e. information processing based on quantum-mechanical phenomena: physical realisations or architectures of quantum processors…