Minimum energy for electric-field reversal of magnetization · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Minimum energy for electric-field reversal of magnetization
Plain
A magnetoelectric memory bit would compete with transistors only if an electric field can flip its magnetization with very little energy. How small that energy can be in principle, given that the bit must stay stable against heat, is not known.
Precise · changed · core
Revision 1: For a single-domain magnetoelectric element of volume $V$ that must remain thermally stable (anisotropy energy $K_u V \ge 40 k_B T$ at $T = 300\,\mathrm{K}$), derive a lower bound $W_{\min}$ on the energy supplied by the electric field to reverse the magnetization deterministically, in terms of the spontaneous polarization $P_s$, coercive field $E_c$, magnetoelectric coupling and $V$, and determine whether $W_{\min}$ can lie below about $1e-11\,\mathrm{erg}$ with a bias below about $3e-4\,\mathrm{statvolt}$. An answer is the bound with its derivation and the material parameters that reach it.
Revision 2: For a single-domain magnetoelectric element of volume $V$ that must remain thermally stable (anisotropy energy $K_u V \ge 40 k_B T$ at $T = 300\,\mathrm{K}$), derive a lower bound $W_{\min}$ on the energy supplied by the electric field to reverse the magnetization deterministically, in terms of the spontaneous polarization $P_s$, coercive field $E_c$, magnetoelectric coupling and $V$, and determine whether $W_{\min}$ can lie below about $10^{-11}\,\mathrm{erg}$ with a bias below about $3 \times 10^{-4}\,\mathrm{statvolt}$. An answer is the bound with its derivation and the material parameters that reach it.
Settled by
A thermodynamic derivation of $W_{min}$ checked against measured switching energies in scaled magnetoelectric stacks.
Kind
well-posed
Answer type
value
References
(empty)
Literature status
open
Status note · changed
Revision 1: A target of about 1e-11 erg per bit at about 3e-4 statvolt was set for magnetoelectric spin-orbit logic (Manipatruni et al., Nature 2019).
Revision 2: A target of about $10^{-11}$ erg per bit at about $3 \times 10^{-4}$ statvolt was set for magnetoelectric spin-orbit logic (Manipatruni et al., Nature 2019).
Posed since
2019

Decisions