A CNOT gate between multiphoton qubits encoded in two cavities

Serge Rosenblum 1 Yvonne Gao 1 Philip Reinhold 1 Chen Wang 1 Christopher Axline 1 Luigi Frunzio 1 Steven Girvin 1 Liang Jiang 1 Mazyar Mirrahimi 2 Michel Devoret 1 Robert Schoelkopf 1
2 QUANTIC - QUANTum Information Circuits
MINES ParisTech - École nationale supérieure des mines de Paris, ENS Paris - École normale supérieure - Paris, SU - Sorbonne Université, Inria de Paris
Abstract : Entangling gates between qubits are a crucial component for performing algorithms in quantum computers. However, any quantum algorithm will ultimately have to operate on error-protected logical qubits, which are effective qubits encoded in a high-dimensional Hilbert space. A common approach is to encode logical qubits in collective states of multiple two-level systems, but algorithms operating on multiple logical qubits are highly complex and have not yet been demonstrated. Here, we experimentally realize a controlled NOT (CNOT) gate between two multiphoton qubits in two microwave cavities. In this approach, we encode a qubit in the large Hilbert space of a single cavity mode, rather than in multiple two-level systems. We couple two such encoded qubits together through a transmon, which is driven with an RF pump to apply the CNOT gate within 190 ns. This is two orders of magnitude shorter than the decoherence time of any part of the system, enabling high-fidelity operations comparable to state-of-the-art gates between two-level systems. These results are an important step towards universal algorithms on error-corrected logical qubits.
Complete list of metadatas

Contributor : Mazyar Mirrahimi <>
Submitted on : Thursday, November 30, 2017 - 4:31:58 PM
Last modification on : Wednesday, May 15, 2019 - 4:04:21 AM

Links full text



Serge Rosenblum, Yvonne Gao, Philip Reinhold, Chen Wang, Christopher Axline, et al.. A CNOT gate between multiphoton qubits encoded in two cavities. Nature Communications, Nature Publishing Group, 2018, ⟨10.1038/s41467-018-03059-5⟩. ⟨hal-01652773⟩



Record views