Spin-momentum entanglement in a Bose–Einstein condensate

Kale, Sumit Suresh; Ding, Yijue; Chen, Yong P.; Friedrich, Břetislav; Kais, Sabre

doi:10.1039/d0cp03945d

Cited by 3 publications

(3 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This process induces, in addition, a change in the momentum of the atom by 2 k r , where k r is the photon recoil momentum. , Thus, the atoms are dressed into a superposition of hyperfine spin and mechanical momenta. In our previous work, we analyzed the spin–orbit coupling in the BECs that realize a pair of qutrits. The Hamiltonian , that describes such a spin ( m f )momentum ( K ) coupling can be written in the coupled basis | m f , K ⟩ = {|−1, q + 2 K r ⟩, |0, q ⟩, |+1, q – 2 k r ⟩} as Here, m is the mass of 87 Rb, q is the quasi-momentum (usually at the minimum of the BEC’s lowest energy band), Ω r is the strength of the Raman coupling (which determines the Rabi frequency for the Raman transition between two hyperfine m f states), δ( B ) is the detuning of the Raman laser, ϵ( B ) = 0.65 E r is the quadratic Zeeman shift (at | B ⃗ bias | ≈ 5 G ), E r = ℏ k r 2 /2 m is the recoil energy, and B is the strength of the external magnetic field.…”

Section: Using Raman Coupling To Achieve Superpositionmentioning

confidence: 99%

“…12,13 Thus, the atoms are dressed into a superposition of hyperfine spin and mechanical momenta. In our previous work, 14 we analyzed the spin−orbit coupling in the BECs that realize a pair of qutrits. The Hamiltonian 12,13 that describes such a spin (m f )momentum (K) coupling can be written in the coupled basis |m f , K⟩ = {|−1, q + 2K r ⟩, |0, q⟩, | +1, q − 2k r ⟩} as i k j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j y { z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z…”

mentioning

confidence: 99%

See 1 more Smart Citation

Constructive Quantum Interference in Photochemical Reactions

Kale

Chen

Kais

2021

J. Chem. Theory Comput.

Self Cite

View full text Add to dashboard Cite

Interferences emerge when multiple pathways coexist together, leading toward the same result. Here, we report a theoretical study for a reaction scheme that leads to constructive quantum interference in a photoassociation (PA) reaction of a 87Rb Bose–Einstein condensate where the reactant spin state is prepared in a coherent superposition of multiple bare spin states. This is achieved by changing the reactive scattering channel in the PA reaction. As the origin of coherent control comes from the spin part of the wavefunction, we show that it is sufficient to use radio frequency (RF) coupling to achieve the superposition state. We simulate the RF coupling on a quantum processor (IBMQ Lima), and our results show that interferences can be used as a resource for the coherent control of photochemical reactions. The approach is general and can be employed to study a wide spectrum of chemical reactions in the ultracold regime.

show abstract

Section: Using Raman Coupling To Achieve Superpositionmentioning

confidence: 99%

mentioning

confidence: 99%

Constructive Quantum Interference in Photochemical Reactions

Kale

Chen

Kais

2021

J. Chem. Theory Comput.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This article focuses on achieving the ground state of Kagome lattices using a variational quantum eigensolver (VQE). Such quantum simulations, variational and otherwise, have become quite popular in recent years and been performed for a variety of other systems using diverse methodologies. − However, even constructing the ground state of a single plaquette within the Kagome lattice requires 12 qubits. Various studies , have demonstrated that when attempting to attain the ground state of Hamiltonians with a significant number of qubits (>8), any Hamiltonian-agnostic ansatz, beyond a certain depth, inevitably leads to a barren plateau.…”

Section: Introductionmentioning

confidence: 99%

Physics-Inspired Quantum Simulation of Resonating Valence Bond States─A Prototypical Template for a Spin-Liquid Ground State

Sajjan,

Gupta,

Kale

et al. 2023

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

Spin liquids�an emergent, exotic collective phase of matter�have garnered enormous attention in recent years. While experimentally many prospective candidates have been proposed and realized, theoretically modeling real materials that display such behavior may pose serious challenges due to the inherently high correlation content of such phases. Over the last few decades, the second-quantum revolution has been the harbinger of a novel computational paradigm capable of initiating a foundational evolution in computational physics. In this report, we strive to use the power of the latter to study a prototypical model, a spin-1/2-unit cell of a Kagome antiferromagnet. Extended lattices of such unit cells are known to possess a magnetically disordered spin-liquid ground state. We employ robust classical numerical techniques such as the density-matrix renormalization group (DMRG) to identify the nature of the ground state through a matrix-product state (MPS) formulation. We subsequently use the gained insight to construct an auxiliary Hamiltonian with reduced measurables and also design an ansatz that is modular and gate-efficient. With robust error-mitigation strategies, we are able to demonstrate that the said ansatz is capable of accurately representing the target ground state even on a real IBMQ backend within 1% accuracy in energy. Since the protocol is linearly scaling O(n) in the number of unit cells, gate requirements, and the number of measurements, it is straightforwardly extendable to larger Kagome lattices that can pave the way for efficient construction of spin-liquid ground states on a quantum device.

show abstract

Dynamics of spin-momentum entanglement from superradiant phase transitions

Chelpanova,

Seetharam,

Rosa-Medina

et al. 2024

Phys. Rev. Research

View full text Add to dashboard Cite

Exploring operational regimes of many-body cavity QED with multilevel atoms remains an exciting research frontier for their enhanced storage capabilities of intralevel quantum correlations. In this work, we consider an experimentally feasible many-body cavity QED model describing a four-level system, where each of those levels is formed from a combination of different spin and momentum states of ultracold atoms in a cavity. The resulting model comprises a pair of Dicke Hamiltonians constructed from pseudospin operators, effectively capturing two intertwined superradiant phase transitions. The phase diagram reveals regions featuring weak and strong entangled states of spin and momentum atomic degrees of freedom. These states exhibit different dynamical responses, ranging from slow to fast relaxation, with the added option of persistent entanglement temporal oscillations. We discuss the role of cavity losses in steering the system's dynamics into such entangled states and propose a readout scheme that leverages different light polarizations within the cavity. Our work paves the way to connect the rich variety of non-equilibrium phase transitions that occur in many-body cavity QED to the buildup of quantum correlations in systems with multilevel atom descriptions. Published by the American Physical Society 2024

show abstract

Spin-momentum entanglement in a Bose–Einstein condensate

Abstract: Entanglement is at the core of quantum information processing and may prove essential for quantum speed-up. Inspired by both theoretical and experimental studies of spin-momentum coupling in systems of ultra-cold...

Cited by 3 publications

References 35 publications

Constructive Quantum Interference in Photochemical Reactions

Constructive Quantum Interference in Photochemical Reactions

Physics-Inspired Quantum Simulation of Resonating Valence Bond States─A Prototypical Template for a Spin-Liquid Ground State

Dynamics of spin-momentum entanglement from superradiant phase transitions

Contact Info

Product

Resources

About