Experimental demonstration of composite pulses on IBM's quantum computer

Abstract

We perform comprehensive experimental tests of various composite pulse sequences using one of open-access IBM's quantum processors, based on superconducting transmon qubits. We implement explicit pulse control of the qubit by making use of the opportunity of low-level access to the backend, provided by IBM Quantum. We obtain the excitation profiles for a huge variety of broadband, narrowband, and passband composite pulses, producing any pre-chosen target probabilities, ranging from zero to one. We also test universal composite pulses which compensate errors in any experimental parameter. In all experiments, we find excellent agreement between theoretical and experimental excitation profiles. This proves both the composite pulses as a very efficient and flexible quantum control tool and the high quality of the IBM quantum processor. As an extreme example, we test and observe a pronounced narrowband excitation profile for a composite sequence of as many as 1001 pulses.

Detuning modulated composite segments for robust optical frequency conversion

“…Another scheme for robust frequency conversion that was suggested recently is the composite segmented (CS) scheme, which was adopted from NMR. In the past half a century, rich research activities in NMR allowed the use of composite pulses schemes for robust control and preparation of a desired superposition state in atomic two-level systems [19,20], and for coherent quantum control [21][22][23][24][25][26]. In the NLO realm, Rangelov et al [27] and Erlich et al [28] showed numerically and experimentally that a novel method using a CS crystal design based on the NMR composite pulses scheme of Shaka and Pines [29] can be used in NLO to create a broadband and robust second harmonic generation (SHG) process.…”

Generalized hyper-Ramsey-Bordé matter-wave interferometry: quantum engineering of robust atomic sensors with composite pulses

“…Various signal distortions from rf field inhomogeneities, offresonance effects and field amplitude error were reduced to a very low order of correction by means of complex sequences of pulses adapted to single or even dual compensation of these systematics. Composite pulses have also demonstrated to be useful for robust error compensation in high-fidelity qubit gates dedicated to quantum computation [27][28][29][30][31].…”

Narrowband composite two-qubit phase gates

“…First developed in nuclear magnetic resonance (NMR) [1] and its analogue even earlier in polarization optics [2], their efficiency was soon largely acknowledged. In the last two decades, they have been successfully applied in other areas, such as trapped ions [3][4][5][6][7][8][9][10], neutral atoms [11,12], quantum dots [13][14][15][16][17][18], NV centers in diamond [19], doped solids [20][21][22][23], superconducting qubits [24,25], optical clocks [26], atom optics [27][28][29], magnetometry [30], optomechanics [31], etc.…”

“…Traditionally, composite pulses are primarily used to achieve broadband excitation profiles [25,[32][33][34] with high fidelity, robust to deviations in certain experimental parameters, such as the amplitude, frequency and duration of the external driving pulsed fields. Recently, composite pulses which are robust to deviations in any parameter have been designed and demonstrated [21].…”

“…Recently, composite pulses which are robust to deviations in any parameter have been designed and demonstrated [21]. However, one may also use composite pulses to achieve narrowband profiles [25,[33][34][35] for highly selective excitation only within a narrow range of a certain parameter value. A combination of broadband and narrowband features are offered by passband composite pulses [34,36], which lie between these two extremes.…”