A single-photon switch and transistor enabled by a solid-state quantum memory

Single-photon switches and transistors generate strong photon-photon interactions that are essential for quantum circuits and networks. However, the deterministic control of an optical signal with a single photon requires strong interactions with a quantum memory, which has been challenging to achieve in a solid-state platform. We demonstrate a single-photon switch and transistor enabled by a solid-state quantum memory. Our device consists of a semiconductor spin qubit strongly coupled to a nanophotonic cavity. The spin qubit enables a single 63-picosecond gate photon to switch a signal field containing up to an average of 27.7 photons before the internal state of the device resets. Our results show that semiconductor nanophotonic devices can produce strong and controlled photon-photon interactions that could enable high-bandwidth photonic quantum information processing.

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A long-lived solid-state quantum memory at the single photon level

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting ◽

10.1364/qim.2013.w6.02 ◽

2013 ◽

Author(s):

Nuala Timoney ◽

Imam Usmani ◽

Pierre Jobez ◽

Mikael Afzelius ◽

Nicolas Gisin

Keyword(s):

Solid State ◽

Single Photon ◽

Quantum Memory

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DECOHERENCE-FREE QUANTUM MEMORY FOR PHOTONIC STATE USING ATOMIC ENSEMBLES

International Journal of Quantum Information ◽

10.1142/s021974990900547x ◽

2009 ◽

Vol 07 (04) ◽

pp. 811-820 ◽

Cited By ~ 2

Author(s):

FENG MEI ◽

YA-FEI YU ◽

ZHI-MING ZHANG

Keyword(s):

Information Processing ◽

Quantum Information ◽

Large Scale ◽

Quantum Information Processing ◽

Single Photon ◽

Quantum Memory ◽

Single Photon Detection ◽

Atomic Ensembles ◽

Optical Elements ◽

Photonic State

Large scale quantum information processing requires stable and long-lived quantum memories. Here, using atom-photon entanglement, we propose an experimentally feasible scheme to realize decoherence-free quantum memory with atomic ensembles, and show one of its applications, remote transfer of unknown quantum state, based on laser manipulation of atomic ensembles, photonic state operation through optical elements, and single-photon detection with moderate efficiency. The scheme, with inherent fault-tolerance to the practical noise and imperfections, allows one to retrieve the information in the memory for further quantum information processing within the reach of current technology.

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Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory

Nature Communications ◽

10.1038/ncomms9652 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 32

Author(s):

Jian-Shun Tang ◽

Zong-Quan Zhou ◽

Yi-Tao Wang ◽

Yu-Long Li ◽

Xiao Liu ◽

...

Keyword(s):

Solid State ◽

Quantum Dot ◽

Single Photon ◽

Quantum Memory

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Engineering Electronic Structure to Protect Phase Memory in Molecular Qubits by Minimising Orbital Angular Momentum

10.26434/chemrxiv.7067645.v1 ◽

2018 ◽

Cited By ~ 1

Author(s):

Ana Maria Ariciu ◽

David H. Woen ◽

Daniel N. Huh ◽

Lydia Nodaraki ◽

Andreas Kostopoulos ◽

...

Keyword(s):

Electron Spin ◽

Quantum Coherence ◽

Quantum Information Processing ◽

Pulse Sequences ◽

Grover Algorithm ◽

Ligand Shell ◽

Information Strategies ◽

Spin Qubit ◽

Molecular Spin ◽

The Impact

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

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