Extensive characterization of a family of efficient three-qubit gates at the coherence limit

• URL: http://arxiv.org/abs/2207.02938v1
• Date: Wed, 6 Jul 2022 19:42:29 GMT
• Title: Extensive characterization of a family of efficient three-qubit gates at the coherence limit
• Authors: Christopher W. Warren, Jorge Fern\'andez-Pend\'as, Shahnawaz Ahmed, Tahereh Abad, Andreas Bengtsson, Janka Bizn\'arov\'a, Kamanasish Debnath, Xiu Gu, Christian Kri\v{z}an, Amr Osman, Anita Fadavi Roudsari, Per Delsing, G\"oran Johansson, Anton Frisk Kockum, Giovanna Tancredi, Jonas Bylander
• Abstract summary: We implement a three-qubit gate by simultaneously applying two-qubit operations. We generate two classes of entangled states, the GHZ and W states, by applying the new gate only once. We analyze the experimental and statistical errors on the fidelity of the gates and of the target states.
• Score: 0.4471952592011114
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: While all quantum algorithms can be expressed in terms of single-qubit and two-qubit gates, more expressive gate sets can help reduce the algorithmic depth. This is important in the presence of gate errors, especially those due to decoherence. Using superconducting qubits, we have implemented a three-qubit gate by simultaneously applying two-qubit operations, thereby realizing a three-body interaction. This method straightforwardly extends to other quantum hardware architectures, requires only a "firmware" upgrade to implement, and is faster than its constituent two-qubit gates. The three-qubit gate represents an entire family of operations, creating flexibility in quantum-circuit compilation. We demonstrate a gate fidelity of $97.90\%$, which is near the coherence limit of our device. We then generate two classes of entangled states, the GHZ and W states, by applying the new gate only once; in comparison, decompositions into the standard gate set would have a two-qubit gate depth of two and three, respectively. Finally, we combine characterization methods and analyze the experimental and statistical errors on the fidelity of the gates and of the target states.

Related papers

• One Gate Scheme to Rule Them All: Introducing a Complex Yet Reduced Instruction Set for Quantum Computing [8.478982715648547]
  Scheme for qubits with $XX+YY$ coupling realizes any two-qubit gate up to single-qubit gates. We observe marked improvements across various applications, including generic $n$-qubit gate synthesis, quantum volume, and qubit routing.
  arXiv  Detail & Related papers  (2023-12-09T19:30:31Z)
• Quantum control landscape for generation of $H$ and $T$ gates in an open qubit with both coherent and environmental drive [57.70351255180495]
  An important problem in quantum computation is generation of single-qubit quantum gates such as Hadamard ($H$) and $pi/8$ ($T$) Here we consider the problem of optimal generation of $H$ and $T$ gates using coherent control and the environment as a resource acting on the qubit via incoherent control.
  arXiv  Detail & Related papers  (2023-09-05T09:05:27Z)
• High-fidelity parallel entangling gates on a neutral atom quantum computer [41.74498230885008]
  We report the realization of two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel. These advances lay the groundwork for large-scale implementation of quantum algorithms, error-corrected circuits, and digital simulations.
  arXiv  Detail & Related papers  (2023-04-11T18:00:04Z)
• Dancing the Quantum Waltz: Compiling Three-Qubit Gates on Four Level Architectures [0.0]
  We present direct-to-pulse implementations of several three-qubit gates, synthesized via optimal control, for compilation of three-qubit gates onto a superconducting-based architecture. We demonstrate strategies that temporarily use higher level states to perform Toffoli gates and always use higher level states to improve fidelities for quantum circuits.
  arXiv  Detail & Related papers  (2023-03-24T15:28:06Z)
• Universal qudit gate synthesis for transmons [44.22241766275732]
  We design a superconducting qudit-based quantum processor. We propose a universal gate set featuring a two-qudit cross-resonance entangling gate. We numerically demonstrate the synthesis of $rm SU(16)$ gates for noisy quantum hardware.
  arXiv  Detail & Related papers  (2022-12-08T18:59:53Z)
• Low-depth Circuit Implementation of Parity Constraints for Quantum Optimization [0.0]
  We present a construction for circuits with low gate count and depth. The circuits can be implemented on any quantum device with nearest-neighbor connectivity on a square-lattice. We find an upper bound for the circuit depth which is independent of the system size.
  arXiv  Detail & Related papers  (2022-11-21T09:29:07Z)
• Optimal model for fewer-qubit CNOT gates with Rydberg atoms [8.01045083320546]
  We report an optimal model about universal two- and three-qubit CNOT gates mediated by excitation to Rydberg states. Compared to conventional multi-pulse piecewise schemes, our gate can be realized by simultaneous excitation of atoms to the Rydberg states.
  arXiv  Detail & Related papers  (2021-12-16T09:54:52Z)
• Software mitigation of coherent two-qubit gate errors [55.878249096379804]
  Two-qubit gates are important components of quantum computing. But unwanted interactions between qubits (so-called parasitic gates) can degrade the performance of quantum applications. We present two software methods to mitigate parasitic two-qubit gate errors.
  arXiv  Detail & Related papers  (2021-11-08T17:37:27Z)
• Fast multi-qubit gates through simultaneous two-qubit gates [0.5949967357689445]
  Near-term quantum computers are limited by the decoherence of qubits to only being able to run low-depth quantum circuits with acceptable fidelity. One way to overcome these limitations is to expand the available gate set from single- and two-qubit gates to multi-qubit gates. We show that such multi-qubit gates can be realized by the simultaneous application of multiple two-qubit gates to a group of qubits.
  arXiv  Detail & Related papers  (2021-08-25T17:24:31Z)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• Improving the Performance of Deep Quantum Optimization Algorithms with Continuous Gate Sets [47.00474212574662]
  Variational quantum algorithms are believed to be promising for solving computationally hard problems. In this paper, we experimentally investigate the circuit-depth-dependent performance of QAOA applied to exact-cover problem instances. Our results demonstrate that the use of continuous gate sets may be a key component in extending the impact of near-term quantum computers.
  arXiv  Detail & Related papers  (2020-05-11T17:20:51Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.