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:quant-ph/0205174 · Physical Review Letters

Scalable Solid-State Quantum Processor Using Subradiant Two-Atom States

David Petrosyan, Gershon Kurizki

Published Oct 24, 2002• 55 citations
arXivHTMLPDF

Abstract

We propose a realization of a scalable, high-performance quantum processor whose qubits are represented by the ground and subradiant states of effective dimers formed by pairs of two-level systems coupled by resonant dipole-dipole interaction. The dimers are implanted in low-temperature solid host material at controllable nanoscale separations. The two-qubit entanglement either relies on the coherent excitation exchange between the dimers or is mediated by external laser fields.

DOI
10.1103/physrevlett.89.207902

Related papers

Quantum computer with dipole-dipole interacting two-level systems

David Petrosyan, Gershon Kurizki

A scalable, high-performance quantum processor can be implemented using near-resonant dipole-dipole interacting dopants in a transparent solid state host. In this scheme, the qubits are represented by ground and subradiant states of effective dimers formed by pairs of closely spaced two-level systems, while the two-qubit entanglement either relies on the coherent excitation exchange between the dimers or is mediated by external laser fields.

arXiv:quant-ph/0411188•Quantum Information and Computation•Jan 1, 2006•3 citations

Fast Quantum Gates for Neutral Atoms Separated by a Few Tens of Micrometers

Matteo Bergonzoni, Rosario Roberto Riso, Guido Pupillo

We present a theoretical scheme for a family of fast and high-fidelity two-qubit iSWAP gates between neutral atoms separated by more than 20 um, enabled by resonant dipole-dipole spin-exchange interactions between Rydberg states. The protocol harnesses coherent excitation-exchange-deexcitation dynamics between the qubit and the Rydberg states within a single and smooth laser pulse, in the presence of strong dipole-dipole interactions. We utilize optimal control methods to achieve theoretical gate fidelities and durations comparable to blockade-based gates in the presence of relevant noise, while extending the effective interaction range by an order of magnitude. This enables entanglement well beyond the blockade radius, offering a route toward fast, high-connectivity quantum processors.

quant-pharXiv:2511.20437•Physical Review Research•Nov 26, 2025•1 citation

Laser-induced control of multiatom entanglement and decoherence (Invited Paper)

Gershon Kurizki, Abraham G. Kofman, S. Pellegrin +1 more

A scalable multatom entangled system, capable of high-performance quantum computations, can be realized by resonant dipole-dipole interacting dopants in a solid state host. In one realization, the qubits are represented by ground and subradiant states of effective dimers formed by pairs of closely spaced two-level systems (TLS). Such qubits are highly robust against radiative decay. The two-qubit entanglement in this scheme relies on coherent excitation exchange between the dimers by external laser fields. This scheme is challenging because of the nanosize control and addressability it requires. Another realization involves dipole-dipole interacting TLS whose resonance frequency lies in a photonic band gap of a dielectric photonic crystal. A sequence of abrupt changes of the resonance frequency can produce controlled entanglement (logic gates) with improved protection from radiation decay and decoherence.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jul 7, 2005•1 citation

Quantum Interfaces to the Nanoscale

Derek S. Wang, Michael Haas, Prineha Narang

Scalable quantum information systems would store, manipulate, and transmit quantum information locally and across a quantum network, but no single qubit technology is currently robust enough to perform all necessary tasks. Defect centers in solid-state materials have emerged as potential intermediaries between other physical manifestations of qubits, such as superconducting qubits and photonic qubits, to leverage their complementary advantages. It remains an open question, however, how to design and to control quantum interfaces to defect centers. Such interfaces would enable quantum information to be moved seamlessly between different physical systems. Understanding and constructing the required interfaces would, therefore, unlock the next big steps in quantum computing, sensing, and communications. In this Perspective, we highlight promising coupling mechanisms, including dipole-, phonon-, and magnon-mediated interactions, and discuss how contributions from nanotechnologists will be paramount in realizing quantum information processors in the near-term.

ACS Nano•May 17, 2021•20 citations

Silicon quantum processor with robust long-distance qubit couplings

G. Tosi, Fahd A. Mohiyaddin, Vivien Schmitt +4 more

Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.Quantum computers will require a large network of coherent qubits, connected in a noise-resilient way. Tosi et al. present a design for a quantum processor based on electron-nuclear spins in silicon, with electrical control and coupling schemes that simplify qubit fabrication and operation.

arXiv:1509.08538•Nature Communications•Aug 31, 2017•170 citations

Quantum-RAM Implementation Using Multiple Interacting Rydberg-Blockaded EIT Systems

Avirup Chakraborty, Shrabana Chakrabarti

We propose a novel theoretical architecture for implementing a quantum random access memory (qRAM) based on quantum random walks in a Rydberg blockaded atomic ensemble utilizing multilevel Electromagnetically Induced Transparency (EIT). Unlike previous approaches that rely on geometric phase gates in solid-state or trapped ion systems, our scheme harnesses the strong, coherent dipole dipole interactions between Rydberg atoms to achieve high-fidelity phase control of photonic qubits without the need for cryogenic temperatures. By generating conditional phase shifts through cross-phase modulation in multiple lambda-type EIT systems, we realize the controlled unitary operations requisite for an efficient qRAM. In the proposed architecture, Zeeman splitting is used to engineer a set of parallel lambda systems in a cavity, where pairs of magnetic sublevels of the ground state are coupled to highly excited Rydberg states via circularly polarized laser pulses. These Rydberg excited EIT systems serve as the elementary phase gates that form the nodes of a binary tree enabling quantum random walking. Address and data qubits are encoded into distinct probe fields and coherently mapped into the metastable atomic states, where their interactions within the EIT medium generate conditional phases required for state-selective routing. The system uses $n+m$ layers of cold alkali atoms to form an $n$-level binary tree of Rydberg nodes connected to $2^n$ cavity-trapped memory atoms, operated by $n+m$ laser pulses acting as quantum walkers and address units. Our scheme offers a scalable, reducing operational complexity to $\mathcal{O}(n)$ and highly coherent pathway toward photonic qRAM, exploiting collective Rydberg interactions to realize programmable, parallel entangling operations in an atomic ensemble.

quant-pharXiv:2609.11344•Sep 11, 2026•0 citations
We propose a realization of a scalable, high-performance quantum processor whose qubits are represented by the ground and subradiant states of effective dimers formed by pairs of two-level systems coupled by resonant dipole-dipole interaction. The dimers are implanted in low-temperature solid host material at controllable nanoscale separations. The two-qubit entanglement either relies on the coherent excitation exchange between the dimers or is mediated by external laser fields.
We present a theoretical scheme for a family of fast and high-fidelity two-qubit iSWAP gates between neutral atoms separated by more than 20 um, enabled by resonant dipole-dipole spin-exchange interactions between Rydberg states. The protocol harnesses coherent excitation-exchange-deexcitation dynamics between the qubit and the Rydberg states within a single and smooth laser pulse, in the presence of strong dipole-dipole interactions. We utilize optimal control methods to achieve theoretical gate fidelities and durations comparable to blockade-based gates in the presence of relevant noise, while extending the effective interaction range by an order of magnitude. This enables entanglement well beyond the blockade radius, offering a route toward fast, high-connectivity quantum processors.
A scalable multatom entangled system, capable of high-performance quantum computations, can be realized by resonant dipole-dipole interacting dopants in a solid state host. In one realization, the qubits are represented by ground and subradiant states of effective dimers formed by pairs of closely spaced two-level systems (TLS). Such qubits are highly robust against radiative decay. The two-qubit entanglement in this scheme relies on coherent excitation exchange between the dimers by external laser fields. This scheme is challenging because of the nanosize control and addressability it requires. Another realization involves dipole-dipole interacting TLS whose resonance frequency lies in a photonic band gap of a dielectric photonic crystal. A sequence of abrupt changes of the resonance frequency can produce controlled entanglement (logic gates) with improved protection from radiation decay and decoherence.
Scalable quantum information systems would store, manipulate, and transmit quantum information locally and across a quantum network, but no single qubit technology is currently robust enough to perform all necessary tasks. Defect centers in solid-state materials have emerged as potential intermediaries between other physical manifestations of qubits, such as superconducting qubits and photonic qubits, to leverage their complementary advantages. It remains an open question, however, how to design and to control quantum interfaces to defect centers. Such interfaces would enable quantum information to be moved seamlessly between different physical systems. Understanding and constructing the required interfaces would, therefore, unlock the next big steps in quantum computing, sensing, and communications. In this Perspective, we highlight promising coupling mechanisms, including dipole-, phonon-, and magnon-mediated interactions, and discuss how contributions from nanotechnologists will be paramount in realizing quantum information processors in the near-term.
Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves ample space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.Quantum computers will require a large network of coherent qubits, connected in a noise-resilient way. Tosi et al. present a design for a quantum processor based on electron-nuclear spins in silicon, with electrical control and coupling schemes that simplify qubit fabrication and operation.
We propose a novel theoretical architecture for implementing a quantum random access memory (qRAM) based on quantum random walks in a Rydberg blockaded atomic ensemble utilizing multilevel Electromagnetically Induced Transparency (EIT). Unlike previous approaches that rely on geometric phase gates in solid-state or trapped ion systems, our scheme harnesses the strong, coherent dipole dipole interactions between Rydberg atoms to achieve high-fidelity phase control of photonic qubits without the need for cryogenic temperatures. By generating conditional phase shifts through cross-phase modulation in multiple lambda-type EIT systems, we realize the controlled unitary operations requisite for an efficient qRAM. In the proposed architecture, Zeeman splitting is used to engineer a set of parallel lambda systems in a cavity, where pairs of magnetic sublevels of the ground state are coupled to highly excited Rydberg states via circularly polarized laser pulses. These Rydberg excited EIT systems serve as the elementary phase gates that form the nodes of a binary tree enabling quantum random walking. Address and data qubits are encoded into distinct probe fields and coherently mapped into the metastable atomic states, where their interactions within the EIT medium generate conditional phases required for state-selective routing. The system uses n+mn+mn+m layers of cold alkali atoms to form an nnn-level binary tree of Rydberg nodes connected to 2n2^n2n cavity-trapped memory atoms, operated by n+mn+mn+m laser pulses acting as quantum walkers and address units. Our scheme offers a scalable, reducing operational complexity to O(n)\mathcal{O}(n)O(n) and highly coherent pathway toward photonic qRAM, exploiting collective Rydberg interactions to realize programmable, parallel entangling operations in an atomic ensemble.