Limits...
Spin – orbit coupled molecular quantum magnetism realized in inorganic solid

View Article: PubMed Central - PubMed

ABSTRACT

Molecular quantum magnetism involving an isolated spin state is of particular interest due to the characteristic quantum phenomena underlying spin qubits or molecular spintronics for quantum information devices, as demonstrated in magnetic metal–organic molecular systems, the so-called molecular magnets. Here we report the molecular quantum magnetism realized in an inorganic solid Ba3Yb2Zn5O11 with spin–orbit coupled pseudospin-½ Yb3+ ions. The magnetization represents the magnetic quantum values of an isolated Yb4 tetrahedron with a total (pseudo)spin 0, 1 and 2. Inelastic neutron scattering results reveal that a large Dzyaloshinsky–Moriya interaction originating from strong spin–orbit coupling of Yb 4f is a key ingredient to explain magnetic excitations of the molecular magnet states. The Dzyaloshinsky–Moriya interaction allows a non-adiabatic quantum transition between avoided crossing energy levels, and also results in unexpected magnetic behaviours in conventional molecular magnets.

No MeSH data available.


Related in: MedlinePlus

INS results and an energy diagram of a Yb4 molecular tetrahedron.(a,b) INS intensities I(Q, ω) as a function of momentum Q and energy transfer ħω measured using incident neutron energy E=2.27 meV (=6.0 Å) at (a) T=200 mK and (b) T=10 K. (c) Constant-ω cuts I(Q)'s obtained by integrating over ranges of 0.45 meV<ħω<0.60 meV (blue filled circle) and 0.65 meV<ħω<0.80 meV (diamond) at 200 mK. A black dashed line represents the square of the Yb3+ magnetic form factor, and a green dashed line does the model calcution for a Yb4 tetrahedron, which expresses a functional form of 1−sin(Qr)/Qr at r=3.30 Å. (d) Constant-Q cuts I(ω)'s obtained by integrating over a range of 0.8 Å−1<Q<1.8 Å−1 at T=200 mK (blue circle) and T=10 K (red circle). Solid lines present simulated I(ω)'s from the effective Hamiltonian . (e) Schematic energy level diagram extracted from diagonalization of . The degeneracy of each energy level is presented in the paranthesis together with the eigenstate ψ. The excitations with indices from 1 to 10 (vertical red arrows) are observable in I(ω)'s in d. Intensity error bars are square roots of intensities.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5035996&req=5

f2: INS results and an energy diagram of a Yb4 molecular tetrahedron.(a,b) INS intensities I(Q, ω) as a function of momentum Q and energy transfer ħω measured using incident neutron energy E=2.27 meV (=6.0 Å) at (a) T=200 mK and (b) T=10 K. (c) Constant-ω cuts I(Q)'s obtained by integrating over ranges of 0.45 meV<ħω<0.60 meV (blue filled circle) and 0.65 meV<ħω<0.80 meV (diamond) at 200 mK. A black dashed line represents the square of the Yb3+ magnetic form factor, and a green dashed line does the model calcution for a Yb4 tetrahedron, which expresses a functional form of 1−sin(Qr)/Qr at r=3.30 Å. (d) Constant-Q cuts I(ω)'s obtained by integrating over a range of 0.8 Å−1<Q<1.8 Å−1 at T=200 mK (blue circle) and T=10 K (red circle). Solid lines present simulated I(ω)'s from the effective Hamiltonian . (e) Schematic energy level diagram extracted from diagonalization of . The degeneracy of each energy level is presented in the paranthesis together with the eigenstate ψ. The excitations with indices from 1 to 10 (vertical red arrows) are observable in I(ω)'s in d. Intensity error bars are square roots of intensities.

Mentions: To explore magnetic excitations in this novel quantum magnet, we performed INS measurements2021223536. Figure 2a shows the intensities I(Q,ω) as a function of momentum and energy transfer obtained from the measurements at T=200 mK and at the zero magnetic field. The I(Q, ω) exhibits four non-dispersive excitations, which correspond to the transitions from the Seff=0 ground state to the Seff=1 excited states. As temperature increases, the Seff=1 states become partially occupied due to the thermal energy, and additional transitions from the Seff=1 states become available in the INS result. Indeed, we could observe additional non-dispersive excitations at 10 K as shown in Fig. 2b.


Spin – orbit coupled molecular quantum magnetism realized in inorganic solid
INS results and an energy diagram of a Yb4 molecular tetrahedron.(a,b) INS intensities I(Q, ω) as a function of momentum Q and energy transfer ħω measured using incident neutron energy E=2.27 meV (=6.0 Å) at (a) T=200 mK and (b) T=10 K. (c) Constant-ω cuts I(Q)'s obtained by integrating over ranges of 0.45 meV<ħω<0.60 meV (blue filled circle) and 0.65 meV<ħω<0.80 meV (diamond) at 200 mK. A black dashed line represents the square of the Yb3+ magnetic form factor, and a green dashed line does the model calcution for a Yb4 tetrahedron, which expresses a functional form of 1−sin(Qr)/Qr at r=3.30 Å. (d) Constant-Q cuts I(ω)'s obtained by integrating over a range of 0.8 Å−1<Q<1.8 Å−1 at T=200 mK (blue circle) and T=10 K (red circle). Solid lines present simulated I(ω)'s from the effective Hamiltonian . (e) Schematic energy level diagram extracted from diagonalization of . The degeneracy of each energy level is presented in the paranthesis together with the eigenstate ψ. The excitations with indices from 1 to 10 (vertical red arrows) are observable in I(ω)'s in d. Intensity error bars are square roots of intensities.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5035996&req=5

f2: INS results and an energy diagram of a Yb4 molecular tetrahedron.(a,b) INS intensities I(Q, ω) as a function of momentum Q and energy transfer ħω measured using incident neutron energy E=2.27 meV (=6.0 Å) at (a) T=200 mK and (b) T=10 K. (c) Constant-ω cuts I(Q)'s obtained by integrating over ranges of 0.45 meV<ħω<0.60 meV (blue filled circle) and 0.65 meV<ħω<0.80 meV (diamond) at 200 mK. A black dashed line represents the square of the Yb3+ magnetic form factor, and a green dashed line does the model calcution for a Yb4 tetrahedron, which expresses a functional form of 1−sin(Qr)/Qr at r=3.30 Å. (d) Constant-Q cuts I(ω)'s obtained by integrating over a range of 0.8 Å−1<Q<1.8 Å−1 at T=200 mK (blue circle) and T=10 K (red circle). Solid lines present simulated I(ω)'s from the effective Hamiltonian . (e) Schematic energy level diagram extracted from diagonalization of . The degeneracy of each energy level is presented in the paranthesis together with the eigenstate ψ. The excitations with indices from 1 to 10 (vertical red arrows) are observable in I(ω)'s in d. Intensity error bars are square roots of intensities.
Mentions: To explore magnetic excitations in this novel quantum magnet, we performed INS measurements2021223536. Figure 2a shows the intensities I(Q,ω) as a function of momentum and energy transfer obtained from the measurements at T=200 mK and at the zero magnetic field. The I(Q, ω) exhibits four non-dispersive excitations, which correspond to the transitions from the Seff=0 ground state to the Seff=1 excited states. As temperature increases, the Seff=1 states become partially occupied due to the thermal energy, and additional transitions from the Seff=1 states become available in the INS result. Indeed, we could observe additional non-dispersive excitations at 10 K as shown in Fig. 2b.

View Article: PubMed Central - PubMed

ABSTRACT

Molecular quantum magnetism involving an isolated spin state is of particular interest due to the characteristic quantum phenomena underlying spin qubits or molecular spintronics for quantum information devices, as demonstrated in magnetic metal&ndash;organic molecular systems, the so-called molecular magnets. Here we report the molecular quantum magnetism realized in an inorganic solid Ba3Yb2Zn5O11 with spin&ndash;orbit coupled pseudospin-&frac12; Yb3+ ions. The magnetization represents the magnetic quantum values of an isolated Yb4 tetrahedron with a total (pseudo)spin 0, 1 and 2. Inelastic neutron scattering results reveal that a large Dzyaloshinsky&ndash;Moriya interaction originating from strong spin&ndash;orbit coupling of Yb 4f is a key ingredient to explain magnetic excitations of the molecular magnet states. The Dzyaloshinsky&ndash;Moriya interaction allows a non-adiabatic quantum transition between avoided crossing energy levels, and also results in unexpected magnetic behaviours in conventional molecular magnets.

No MeSH data available.


Related in: MedlinePlus