Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1802.05320 · Physical Review A

Entanglement of two noninteracting qubits via a mesoscopic system

Maryam Sadat Mirkamali, David G. Cory, Joseph Emerson

Published Oct 18, 2018• 5 citations
arXivHTMLPDF

Abstract

We propose a method for entangling two noninteracting qubits by measuring their parity indirectly through an intermediate mesoscopic system. The protocol is designed to require only global control and course-grained collective measurement of the mesoscopic system along with local interactions between the target qubits and mesoscopic system. A generalization of the method measures the hamming weight of the qubits' state and probabilistically produces an entangled state by post-selecting on hamming weight one. Our technique provides a design element that can be integrated into quantum processor architectures and quantum measurement devices.

DOI
10.1103/physreva.98.042327

Related papers

Resources Needed for Entangling Two Qubits through an Intermediate Mesoscopic System

Maryam Sadat Mirkamali

One of the main challenges in designing large scale quantum processors is connecting separated qubits. In this thesis, we explore new opportunities that mesoscopic many-body systems provide for creating quantum correlation between isolated quantum systems. In particular, we study entangling two non-interacting qubits through an intermediate mesoscopic system consisting of identical two-level systems. Two uncoupled qubits can be entangled either by projectively measuring a joint property of them or by creating an indirect interaction between them. The focus of this thesis is on procedures that are based on joint measurement on the qubits. \nWe propose a new method for entangling two non-interacting qubits by measuring their parity indirectly through an intermediate mesoscopic system. Indirect joint measurement scheme benefits from coherent magnification of the target qubits’ state in the collective state of the mesoscopic system; such that a low-resolution measurement on the mesoscopic system suffices to prepare post-selected entanglement on the target qubits. The protocol is designed to require only global control and course-grained collective measurement of the mesoscopic system along with local interactions between the target qubits and mesoscopic system. A generalization of the method measures the hamming weight of the qubits’ state and probabilistically produces an entangled state by post-selecting on hamming weight one. Our technique provides a new design element that can be integrated into quantum processor architectures and quantum measurement devices. \nWe quantify the resources required for implementing the indirect joint measurement technique when the intermediate mesoscopic system consists of spin-1/2 particles with internal dipolar coupling. A mesoscopic spin system consisting of two non-interacting halves, each coupled to one of the target qubits is proved to provide a helpful geometry that allows implementing the coherent magnification process with experimentally available control tools. We show that the requirements on the amplified state of the target qubits and the mesoscopic spin system perfectly maps to the specifications of micro-macro entanglement between each target qubit and its nearby half of the mesoscopic spin system. In the light of this equivalence, the effects of experimental imperfections are explored; in particular, bipartite entanglement between the target qubits is shown to be robust to imperfect preparation of the mesoscopic spin system. Our analysis provides a new approach for using an intermediate spin system for connecting separated qubits. It also opens a new path in exploring entanglement between microscopic and mesoscopic spin systems.

•Sep 23, 2019•2 citations

Mesoscopic spin systems as quantum entanglers

Maryam Sadat Mirkamali, David G. Cory

We quantify the resources required for entangling two uncoupled spin qubits through an intermediate mesoscopic spin system (MSS) by indirect joint measurement. Indirect joint measurement benefits from coherent magnification of the target qubits' state in the collective magnetization of the MSS, such that a low-resolution collective measurement on the MSS suffices to prepare postselected entanglement on the target qubits. A MSS consisting of two noninteracting halves, each coupled to one of the target qubits, is identified as a geometry that allows implementing the magnification process with experimentally available control tools. It is proved that the requirements on the amplified state of the target qubits and the MSS perfectly map to the specifications of micro-macro entanglement between each target qubit and its nearby half of the MSS. In the light of this equivalence, the effects of experimental imperfections are explored; in particular, bipartite entanglement between the target qubits is shown to be robust to imperfect preparation of the MSS. Our study provides an approach for using an intermediate spin system for connecting separated qubits. It also opens another path in exploring entanglement between microscopic and mesoscopic spin systems.

arXiv:1910.11326•Physical Review A•Mar 16, 2020•4 citations

Mesoscopic entanglement of noninteracting qubits using collective spontaneous emission

D. Kielpinski

We describe an experimentally straightforward method for preparing an entangled W state of up to 100 qubits. Our repeat-until-success protocol relies on detection of single photons from collective spontaneous emission in free space. Our method allows entanglement preparation in a wide range of qubit implementations that lack entangling qubit-qubit interactions. We give detailed numerical examples for entanglement of neutral atoms in optical lattices and of nitrogen-vacancy centres in diamond. The simplicity of our method should enable preparation of mesoscopic entangled states in a number of physical systems in the near future.

•Jan 12, 2007•2 citations

Mesoscopic entanglement of noninteracting qubits using collective spontaneous emission

D. Kielpinski

We describe an experimentally straightforward method for preparing an entangled W state of at least 100 qubits. Our repeat-until-success protocol relies on detection of single photons from collective spontaneous emission in free space. Our method allows entanglement preparation in a wide range of qubit implementations that lack entangling qubit–qubit interactions. We give detailed numerical examples for entanglement of neutral atoms in optical lattices and of nitrogen-vacancy centres in diamond. The simplicity of our method should enable preparation of mesoscopic entangled states in a number of physical systems in the near future.

arXiv:quant-ph/0701066•New Journal of Physics•Nov 14, 2007•5 citations

Parity meter for charge qubits: An efficient quantum entangler

Björn Trauzettel, Andrew N. Jordan, C. W. J. Beenakker +1 more

We propose a realization of a charge parity meter based on two double quantum dots alongside a quantum point contact. Such a device is a specific example of the general class of mesoscopic quadratic quantum measurement detectors previously investigated by Mao et al. [Phys. Rev. Lett. 93, 056803 (2004)]. Our setup accomplishes entangled state preparation by a current measurement alone, and allows the qubits to be effectively decoupled by pinching off the parity meter. Two applications of the parity meter are discussed: the measurement of Bell's inequality in charge qubits and the realization of a controlled-NOT gate.

arXiv:cond-mat/0602514•Physical Review B•Jun 16, 2006•72 citations

Global control via quantum actuators

Roberto Menta, Francesco Cioni, Riccardo Aiudi +2 more

We introduce the concept of quantum actuators as mediators for globally controlled quantum computation. Auxiliary quantum systems act as controllable elements that transiently store and release interaction energy, enabling the selective activation of multi-qubit gates within globally driven architectures. During compilation they remain passive and require no fine-grained local control, while during operation they allow for controlled activation of interactions and directional flow of quantum information. We provide a framework for embedding quantum actuators in globally controlled processors, showing how they enhance connectivity, enable long-range entangling operations, and bridge distant regions without increasing local control overhead. We discuss physical implementations and architectural strategies illustrating how these elements extend the capabilities of global-control schemes. A complementary interpretation in terms of quantum batteries naturally emerges, connecting global-control architectures with concepts from quantum thermodynamics while highlighting the distinct operational role of quantum actuators.

quant-pharXiv:2603.23362•Mar 25, 2026•0 citations
We propose a method for entangling two noninteracting qubits by measuring their parity indirectly through an intermediate mesoscopic system. The protocol is designed to require only global control and course-grained collective measurement of the mesoscopic system along with local interactions between the target qubits and mesoscopic system. A generalization of the method measures the hamming weight of the qubits' state and probabilistically produces an entangled state by post-selecting on hamming weight one. Our technique provides a design element that can be integrated into quantum processor architectures and quantum measurement devices.
One of the main challenges in designing large scale quantum processors is connecting separated qubits. In this thesis, we explore new opportunities that mesoscopic many-body systems provide for creating quantum correlation between isolated quantum systems. In particular, we study entangling two non-interacting qubits through an intermediate mesoscopic system consisting of identical two-level systems. Two uncoupled qubits can be entangled either by projectively measuring a joint property of them or by creating an indirect interaction between them. The focus of this thesis is on procedures that are based on joint measurement on the qubits. \nWe propose a new method for entangling two non-interacting qubits by measuring their parity indirectly through an intermediate mesoscopic system. Indirect joint measurement scheme benefits from coherent magnification of the target qubits’ state in the collective state of the mesoscopic system; such that a low-resolution measurement on the mesoscopic system suffices to prepare post-selected entanglement on the target qubits. The protocol is designed to require only global control and course-grained collective measurement of the mesoscopic system along with local interactions between the target qubits and mesoscopic system. A generalization of the method measures the hamming weight of the qubits’ state and probabilistically produces an entangled state by post-selecting on hamming weight one. Our technique provides a new design element that can be integrated into quantum processor architectures and quantum measurement devices. \nWe quantify the resources required for implementing the indirect joint measurement technique when the intermediate mesoscopic system consists of spin-1/2 particles with internal dipolar coupling. A mesoscopic spin system consisting of two non-interacting halves, each coupled to one of the target qubits is proved to provide a helpful geometry that allows implementing the coherent magnification process with experimentally available control tools. We show that the requirements on the amplified state of the target qubits and the mesoscopic spin system perfectly maps to the specifications of micro-macro entanglement between each target qubit and its nearby half of the mesoscopic spin system. In the light of this equivalence, the effects of experimental imperfections are explored; in particular, bipartite entanglement between the target qubits is shown to be robust to imperfect preparation of the mesoscopic spin system. Our analysis provides a new approach for using an intermediate spin system for connecting separated qubits. It also opens a new path in exploring entanglement between microscopic and mesoscopic spin systems.
We quantify the resources required for entangling two uncoupled spin qubits through an intermediate mesoscopic spin system (MSS) by indirect joint measurement. Indirect joint measurement benefits from coherent magnification of the target qubits' state in the collective magnetization of the MSS, such that a low-resolution collective measurement on the MSS suffices to prepare postselected entanglement on the target qubits. A MSS consisting of two noninteracting halves, each coupled to one of the target qubits, is identified as a geometry that allows implementing the magnification process with experimentally available control tools. It is proved that the requirements on the amplified state of the target qubits and the MSS perfectly map to the specifications of micro-macro entanglement between each target qubit and its nearby half of the MSS. In the light of this equivalence, the effects of experimental imperfections are explored; in particular, bipartite entanglement between the target qubits is shown to be robust to imperfect preparation of the MSS. Our study provides an approach for using an intermediate spin system for connecting separated qubits. It also opens another path in exploring entanglement between microscopic and mesoscopic spin systems.
We describe an experimentally straightforward method for preparing an entangled W state of up to 100 qubits. Our repeat-until-success protocol relies on detection of single photons from collective spontaneous emission in free space. Our method allows entanglement preparation in a wide range of qubit implementations that lack entangling qubit-qubit interactions. We give detailed numerical examples for entanglement of neutral atoms in optical lattices and of nitrogen-vacancy centres in diamond. The simplicity of our method should enable preparation of mesoscopic entangled states in a number of physical systems in the near future.
We describe an experimentally straightforward method for preparing an entangled W state of at least 100 qubits. Our repeat-until-success protocol relies on detection of single photons from collective spontaneous emission in free space. Our method allows entanglement preparation in a wide range of qubit implementations that lack entangling qubit–qubit interactions. We give detailed numerical examples for entanglement of neutral atoms in optical lattices and of nitrogen-vacancy centres in diamond. The simplicity of our method should enable preparation of mesoscopic entangled states in a number of physical systems in the near future.
We propose a realization of a charge parity meter based on two double quantum dots alongside a quantum point contact. Such a device is a specific example of the general class of mesoscopic quadratic quantum measurement detectors previously investigated by Mao et al. [Phys. Rev. Lett. 93, 056803 (2004)]. Our setup accomplishes entangled state preparation by a current measurement alone, and allows the qubits to be effectively decoupled by pinching off the parity meter. Two applications of the parity meter are discussed: the measurement of Bell's inequality in charge qubits and the realization of a controlled-NOT gate.
We introduce the concept of quantum actuators as mediators for globally controlled quantum computation. Auxiliary quantum systems act as controllable elements that transiently store and release interaction energy, enabling the selective activation of multi-qubit gates within globally driven architectures. During compilation they remain passive and require no fine-grained local control, while during operation they allow for controlled activation of interactions and directional flow of quantum information. We provide a framework for embedding quantum actuators in globally controlled processors, showing how they enhance connectivity, enable long-range entangling operations, and bridge distant regions without increasing local control overhead. We discuss physical implementations and architectural strategies illustrating how these elements extend the capabilities of global-control schemes. A complementary interpretation in terms of quantum batteries naturally emerges, connecting global-control architectures with concepts from quantum thermodynamics while highlighting the distinct operational role of quantum actuators.