175 research outputs found
QASMBench: A Low-level QASM Benchmark Suite for NISQ Evaluation and Simulation
The rapid development of quantum computing (QC) in the NISQ era urgently
demands a low-level benchmark suite and insightful evaluation metrics for
characterizing the properties of prototype NISQ devices, the efficiency of QC
programming compilers, schedulers and assemblers, and the capability of quantum
simulators in a classical computer. In this work, we fill this gap by proposing
a low-level, easy-to-use benchmark suite called QASMBench based on the OpenQASM
assembly representation. It consolidates commonly used quantum routines and
kernels from a variety of domains including chemistry, simulation, linear
algebra, searching, optimization, arithmetic, machine learning, fault
tolerance, cryptography, etc., trading-off between generality and usability. To
analyze these kernels in terms of NISQ device execution, in addition to circuit
width and depth, we propose four circuit metrics including gate density,
retention lifespan, measurement density, and entanglement variance, to extract
more insights about the execution efficiency, the susceptibility to NISQ error,
and the potential gain from machine-specific optimizations. Most of the
QASMBench application code can be launched and verified in IBM-Q directly. With
the help from q-convert, QASMBench can be evaluated on various platforms and
simulation environments. QASMBench is released at:
http://github.com/pnnl/QASMBench
A Synergistic Compilation Workflow for Tackling Crosstalk in Quantum Machines
Near-term quantum systems tend to be noisy. Crosstalk noise has been
recognized as one of several major types of noises in superconducting Noisy
Intermediate-Scale Quantum (NISQ) devices. Crosstalk arises from the concurrent
execution of two-qubit gates on nearby qubits, such as \texttt{CX}. It might
significantly raise the error rate of gates in comparison to running them
individually. Crosstalk can be mitigated through scheduling or hardware machine
tuning. Prior scientific studies, however, manage crosstalk at a really late
phase in the compilation process, usually after hardware mapping is done. It
may miss great opportunities of optimizing algorithm logic, routing, and
crosstalk at the same time. In this paper, we push the envelope by considering
all these factors simultaneously at the very early compilation stage. We
propose a crosstalk-aware quantum program compilation framework called CQC that
can enhance crosstalk mitigation while achieving satisfactory circuit depth.
Moreover, we identify opportunities for translation from intermediate
representation to the circuit for application-specific crosstalk mitigation,
for instance, the \texttt{CX} ladder construction in variational quantum
eigensolvers (VQE). Evaluations through simulation and on real IBM-Q devices
show that our framework can significantly reduce the error rate by up to
6, with only 60\% circuit depth compared to state-of-the-art gate
scheduling approaches. In particular, for VQE, we demonstrate 49\% circuit
depth reduction with 9.6\% fidelity improvement over prior art on the H4
molecule using IBMQ Guadalupe. Our CQC framework will be released on GitHub
CODAR: A Contextual Duration-Aware Qubit Mapping for Various NISQ Devices
Quantum computing devices in the NISQ era share common features and
challenges like limited connectivity between qubits. Since two-qubit gates are
allowed on limited qubit pairs, quantum compilers must transform original
quantum programs to fit the hardware constraints. Previous works on qubit
mapping assume different gates have the same execution duration, which limits
them to explore the parallelism from the program. To address this drawback, we
propose a Multi-architecture Adaptive Quantum Abstract Machine (maQAM) and a
COntext-sensitive and Duration-Aware Remapping algorithm (CODAR). The CODAR
remapper is aware of gate duration difference and program context, enabling it
to extract more parallelism from programs and speed up the quantum programs by
1.23 in simulation on average in different architectures and maintain the
fidelity of circuits when running on Origin Quantum noisy simulator.Comment: arXiv admin note: substantial text overlap with arXiv:2001.0688
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