We propose a scheme for squeezing vibrational wave packets in the ground (or excited) states of diatomic molecules that uses pulse sequences of strong nonresonant short pulses. The physical mechanism of the scheme is a two step process involving adiabatic and diabatic transformations of the wave packet. The first step is the adiabatic stretching of the wave packet on a light-induced potential, and the second step is dynamic squeezing by free evolution after ultrashort (i.e., diabatic) population transfer. We show that this sequence of transformations can be performed very efficiently with a simple two pulse sequence with slow switch on and fast switch off pulse shapes, and we analyze the required physical resources that are needed. We test the scheme on a model of harmonic oscillators and on the ${\mathrm{Rb}}_{2}$ dimer. Finally, different possible generalizations are proposed.We propose a scheme for squeezing vibrational wave packets in the ground (or excited) states of diatomic molecules that uses pulse sequences of strong nonresonant short pulses. The physical mechanism of the scheme is a two step process involving adiabatic and diabatic transformations of the wave packet. The first step is the adiabatic stretching of the wave packet on a light-induced potential, and the second step is dynamic squeezing by free evolution after ultrashort (i.e., diabatic) population transfer. We show that this sequence of transformations can be performed very efficiently with a simple two pulse sequence with slow switch on and fast switch off pulse shapes, and we analyze the required physical resources that are needed. We test the scheme on a model of harmonic oscillators and on the ${\mathrm{Rb}}_{2}$ dimer. Finally, different possible generalizations are proposed.

Physical Review AJan 12, 20066 citations

Resonant Adiabatic Passages of Spin Qubits

Sangchul Oh, Yun-Pil Shim, Mark G. Friesen +1 more

Bulletin of the American Physical SocietyFeb 29, 20120 citations

Path Entropy Changes in Adiabatic Approximation

Jang-il Sohn

By applying adiabatic theorem to a Markovian system, we calculate the adiabatic and diabatic entropy changes along a path. As well known, the total path entropy change is separated into two parts, system and environment entropy changes, $ΔS_{tot} = ΔS_{sys} + ΔS_{env}$ . The environment entropy change, $ΔS_{env}$ , is divided again into two parts, an adiabatic contribution due to work, $ΔS_{\mathcal{W}}$ , and a diabatic contributions due to heat, $ΔS_{\mathcal{Q}}$ . In an adiabatic process, total path entropy change is same with the adiabatic path entropy change, $ΔS_{A}$ , which is given by sum of system entropy change and adiabatic contribution, $ΔS_{A} = ΔS_{sys} + ΔS_{\mathcal{W}}$ . Mathematical form of $ΔS_{A}$ is a type of excess heat entropy change, but $ΔS_{A}$ is due to work. By which, it is shown that the terms adiabatic and non-adiabatic contributions of $ΔS_{na}$ and $ΔS_{a}$ in [Phys. Rev. Lett. {\bf 104}, 090601 (2010)] should be completely switched, $i.e.$ $ΔS_{na} \rightarrow ΔS_{A}$ and $ΔS_{a} \rightarrow ΔS_{\mathcal{Q}}$ in fact.By applying adiabatic theorem to a Markovian system, we calculate the adiabatic and diabatic entropy changes along a path. As well known, the total path entropy change is separated into two parts, system and environment entropy changes, $ΔS_{tot} = ΔS_{sys} + ΔS_{env}$. The environment entropy change, $ΔS_{env}$, is divided again into two parts, an adiabatic contribution due to work, $ΔS_{\mathcal{W}}$, and a diabatic contributions due to heat, $ΔS_{\mathcal{Q}}$. In an adiabatic process, total path entropy change is same with the adiabatic path entropy change, $ΔS_{A}$, which is given by sum of system entropy change and adiabatic contribution, $ΔS_{A} = ΔS_{sys} + ΔS_{\mathcal{W}}$. Mathematical form of $ΔS_{A}$ is a type of excess heat entropy change, but $ΔS_{A}$ is due to work. By which, it is shown that the terms adiabatic and non-adiabatic contributions of $ΔS_{na}$ and $ΔS_{a}$ in [Phys. Rev. Lett. {\bf 104}, 090601 (2010)] should be completely switched, $i.e.$ $ΔS_{na} \rightarrow ΔS_{A}$ and $ΔS_{a} \rightarrow ΔS_{\mathcal{Q}}$ in fact.

arXiv:1208.3948Aug 20, 20120 citations

Solid-State Qubits

David S. Simon

Undergraduate texts in physicsJan 1, 20251 citation

Realization of adiabatic and diabatic CZ gates in superconducting qubits coupled with a tunable coupler*

Huikai Xu, Weiyang Liu, Zhiyuan Li +11 more

High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number. We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength, and demonstrate the CZ gate using two different schemes, adiabatic and diabatic methods. The Clifford based randomized benchmarking (RB) method is used to assess and optimize the CZ gate fidelity. The fidelities of adiabatic and diabatic CZ gates are 99.53(8)% and 98.72(2)%, respectively. We also analyze the errors induced by the decoherence. Comparing to 30 ns duration time of adiabatic CZ gate, the duration time of diabatic CZ gate is 19 ns, revealing lower incoherence error rate r ′ incoherent , int = 0.0197 ( 5 ) compared to r incoherent, int = 0.0223(3).High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number. We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength, and demonstrate the CZ gate using two different schemes, adiabatic and diabatic methods. The Clifford based randomized benchmarking (RB) method is used to assess and optimize the CZ gate fidelity. The fidelities of adiabatic and diabatic CZ gates are 99.53(8)% and 98.72(2)%, respectively. We also analyze the errors induced by the decoherence. Comparing to 30 ns duration time of adiabatic CZ gate, the duration time of diabatic CZ gate is 19 ns, revealing lower incoherence error rate r ′ incoherent , int = 0.0197 ( 5 ) compared to r incoherent, int = 0.0223(3).

arXiv:2010.14053Chinese Physics BMar 19, 202118 citations

Solid State Qubits

János A. Bergou, Mark S. Hillery, Mark E. Saffman

Graduate texts in physicsJan 1, 20210 citations

{\mathrm{Rb}}_{2}

dimer. Finally, different possible generalizations are proposed.

ΔS_{tot} = ΔS_{sys} + ΔS_{env}

. The environment entropy change,

ΔS_{env}

, is divided again into two parts, an adiabatic contribution due to work,

ΔS_{\mathcal{W}}

, and a diabatic contributions due to heat,

ΔS_{\mathcal{Q}}

. In an adiabatic process, total path entropy change is same with the adiabatic path entropy change,

ΔS_{A}

, which is given by sum of system entropy change and adiabatic contribution,

ΔS_{A} = ΔS_{sys} + ΔS_{\mathcal{W}}

. Mathematical form of

ΔS_{A}

is a type of excess heat entropy change, but

ΔS_{A}

is due to work. By which, it is shown that the terms adiabatic and non-adiabatic contributions of

ΔS_{na}

and

ΔS_{a}

in [Phys. Rev. Lett. {\bf 104}, 090601 (2010)] should be completely switched,

i.e.

ΔS_{na} \rightarrow ΔS_{A}

and

ΔS_{a} \rightarrow ΔS_{\mathcal{Q}}

in fact.