Research Publications Archive

The latest in Quantum Thinking

Unlocking a fast adiabatic CZ gate and exact residual ZZ cancellation between fixed-frequency transmons using a floating tunable coupler

In this work, we demonstrate that a symmetric floating tunable coupler provides a natural platform for fast, high-fidelity adiabatic controlled-Z (CZ) gates. Its favorable energy-level structure eliminates the conventional trade-off between rapid conditional-phase accumulation and adiabatic evolution while preserving exact cancellation of residual ZZ interaction at idling.

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Algorithms & Applications 20.08.20

Finding the optimal Nash equilibrium in a discrete Rosenthal congestion game using the Quantum Alternating Operator Ansatz

We establish the tractability of finding the optimal Nash equilibrium to a discrete congestion game using a gate-model quantum computer.

Systems R&D 07.07.20

An open-source, industrial-strength optimizing compiler for quantum programs

We describe many of the principles behind Quilc's design, and demonstrate the compiler with various examples.

Algorithms & Applications 27.02.20

Quanvolutional neural networks: powering image recognition with quantum circuits

We introduce a new type of transformational layer called a quantum convolution, or quanvolutional layer.

Systems R&D 14.01.20

A quantum-classical cloud platform optimized for variational hybrid algorithms

We enumerate the architectural requirements of a quantum-classical cloud platform, and present a framework for benchmarking its runtime performance.

Algorithms & Applications 27.12.19

Quantum logic gate synthesis as a Markov Decision Process

We investigate the feasibility of the assumption that a variety of tasks in quantum programming could be modeled as Markov Decision Processes by exploring its consequences for two of the simplest tasks in quantum programming: state preparation and gate compilation.

Systems R&D 09.12.19

Methods for measuring magnetic flux crosstalk between tunable transmons

We present three measurements that directly quantify the DC and AC flux crosstalk present between tunable transmons.

Algorithms & Applications 13.11.19

Portfolio rebalancing experiments using the Quantum Alternating Operator Ansatz

Experimental analysis demonstrates the potential tractability of this application on NISQ hardware.

Algorithms & Applications 23.10.19

An approximate description of quantum states

We introduce an approximate description of an N--qubit state, which contains sufficient information to estimate the expectation value of any observable with precision.

Systems R&D 29.08.19

Assessing the influence of broadband instrumentation noise on parametrically modulated superconducting qubits

Low-pass filtering the AC signal used to drive two-qubit gates between the first and second harmonic frequencies can reduce qubit sensitivity to flux noise at the AC sweet spot.

Algorithms & Applications 21.08.19

Automated quantum programming via reinforcement learning for combinatorial optimization

Agents trained through RL techniques are capable of producing short quantum programs with high quality solutions.

Systems R&D 07.05.19

Integrating high-density microwave signalling and packaging with superconducting qubits

Using RF flexible circuits to increase signal density in the dilution refrigerator and package while maintaining signal integrity.

Algorithms & Applications 23.04.19

Fixed-depth two-qubit circuits and the monodromy polytope

We highlight a certain member of the "XY-family" for which many two-qubit programs admit expression as low-depth circuits.

Displaying 61–72 of 83 results