Four-state ferroelectric spin-valve

Spin-valves had empowered the giant magnetoresistance (GMR) devices to have memory. The insertion of thin antiferromagnetic (AFM) films allowed two stable magnetic field-induced switchable resistance states persisting in remanence. In this letter, we show that, without the deliberate introduction of such an AFM layer, this functionality is transferred to multiferroic tunnel junctions (MFTJ) allowing us to create a four-state resistive memory device. We observed that the ferroelectric/ferromagnetic interface plays a crucial role in the stabilization of the exchange bias, which ultimately leads to four robust electro tunnel electro resistance (TER) and tunnel magneto resistance (TMR) states in the junction.

[1]  D.A. Rich,et al.  A four-state ROM using multilevel process technology , 1984, IEEE Journal of Solid-State Circuits.

[2]  William J. Gallagher,et al.  Exchange-biased magnetic tunnel junctions and application to nonvolatile magnetic random access memory (invited) , 1999 .

[3]  V. Speriosu,et al.  Spin-valve RAM cell , 1995 .

[4]  D. Ciudad,et al.  Sign Control of Magnetoresistance Through Chemically Engineered Interfaces , 2014, Advanced materials.

[5]  Binasch,et al.  Enhanced magnetoresistance in layered magnetic structures with antiferromagnetic interlayer exchange. , 1989, Physical review. B, Condensed matter.

[6]  Jordi Sort,et al.  Exchange bias in nanostructures , 2005 .

[7]  W. Meiklejohn.  Exchange Anisotropy—A Review , 1962 .

[8]  P. Torelli,et al.  Electric control of magnetism at the Fe/BaTiO3 interface , 2014, Nature Communications.

[9]  Etienne,et al.  Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices. , 1988, Physical review letters.

[10]  M. Alexe,et al.  Reversible electrical switching of spin polarization in multiferroic tunnel junctions. , 2012, Nature materials.

[11]  A. Fert,et al.  Tunnel junctions with multiferroic barriers. , 2007, Nature materials.

[12]  N. D. Mathur,et al.  Ferroelectric Control of Spin Polarization , 2010, Science.

[13]  Interface-modification-enhanced tunnel electroresistance in multiferroic tunnel junctions , 2014 .

[14]  E. Karlsson.  The Nobel Prize in Physics , 2001 .

[15]  E. Tsymbal,et al.  Spin-Dependent Tunneling in Magnetic Tunnel Junctions , 2003 .

[16]  James Daughton,et al.  Magnetoresistive Random Access Memory (MRAM) , 2000 .

[17]  前川 禎通,et al.  Spin dependent transport in magnetic nanostructures , 2002 .

[18]  H. M. Jang,et al.  Four-states multiferroic memory embodied using Mn-doped BaTiO3 nanorods. , 2013, ACS nano.

[19]  I. Mertig,et al.  Magnetic phase transition in two-phase multiferroics predicted from first principles , 2008 .

[20]  Applications of Magnetic Nanostructures , 2002 .

[21]  W. Brinkman,et al.  Tunneling Conductance of Asymmetrical Barriers , 1970 .

[22]  Stuart S. P. Parkin,et al.  Giant Magnetoresistance in Magnetic Nanostructures , 1995 .

[23]  A Gloter,et al.  Interface-induced room-temperature multiferroicity in BaTiO₃. , 2011, Nature materials.

[24]  Xuejun Zheng,et al.  Eight logic states of tunneling magnetoelectroresistance in multiferroic tunnel junctions , 2007 .

[25]  Horst Rogalla,et al.  Quasi-ideal strontium titanate crystal surfaces through formation of strontium hydroxide , 1998 .

[26]  A. Petraru,et al.  Crossing an Interface: Ferroelectric Control of Tunnel Currents in Magnetic Complex Oxide Heterostructures , 2010 .

[27]  V. Garcia,et al.  Giant tunnel electroresistance for non-destructive readout of ferroelectric states , 2009, Nature.

[28]  Gurney,et al.  Giant magnetoresistive in soft ferromagnetic multilayers. , 1991, Physical review. B, Condensed matter.

[29]  Multiferroic Iron Oxide Thin Films at Room Temperature , 2014, Advanced materials.

[30]  Hermann Kohlstedt,et al.  Tunneling Across a Ferroelectric , 2006, Science.